application spotlight on analogue and sensing · application spotlight on analogue and sensing. ......

Board of the Month: page 21 New NXP LPC1500 development board hostsadvanced LPCXpresso™ development software

Application Spotlight: pages 11-20MEMS barometer from STMicroelectronics canmeasure changes in altitude as small as 1cm

Component Focus: pages 2-9 Microchip simplifies design of three-phase BLDCmotors with highly integrated new power device

Technical View: pages 22-23 How to control power to six strings of LEDs with a single controller IC

Application Spotlight on

Analogue andSensing

MOSFET driver features adaptivedead-time for high efficiencyMicrel has introduced the MIC4605, an 85Vhalf-bridge MOSFET driver which featuresadaptive dead-time and shoot-throughprotection. The adaptive dead-time circuitryhelps to improve power efficiency, and theshoot-through protection preventserroneous inputs and noise from turningboth MOSFETs on at the same time.

Future Electronics to sell CentralSemiconductor products in EMEACentral Semiconductor has expanded itsdistribution agreement with FutureElectronics into EMEA. Future Electronicshas been a franchised distributor of CentralSemiconductor in North America for ten years.

Central Semiconductor’s product rangeincludes energy-efficient and miniaturediscrete semiconductors and custom multi-discrete modules.

Wolfson audio hub brings MasterHi-Fi audio to mobile devicesWolfson Microelectronics has announcedthe introduction of the WM5102S audio hub.It will enable consumers to experience 24-bit,192kHz high-resolution Master Hi-Fi™ audioplayback on a mobile device.

The WM5102S features a class-leading120dB signal-to-noise ratio and integratesWolfson’s advanced Master Hi-Fi filters,which are optimised for authentic playbackof 24-bit Studio Master recordings.

S T A R P R O D U C T

2 E M A I L I N F O @ M Y - F T M . C O M F O R S A M P L E S A N D D A T A S H E E T S

NXP SEMICONDUCTORS

my-ftm.com/140301FOR MOREINFORMATION

©Copyright 2014 Future Electronics Ltd. All trademarks contained herein arethe property of their respective owners. Applications for product samples,badge boards, demonstration boards, Future-Blox Boards and otheradvertised materials from Future Electronics are subject to qualification.

Newsin brief

Triac power switches withstand up to 2kV surges

The ACTT8-800C0, ACTT8X-800C0 andACTT8B-800C0 are AC thyristor triac powerswitches with clamping capabilities whichprotect them against low- and high-energytransients. They are ideal for use in applications

A real-time clock block, resident in a separatealways-on clock domain, is suitable for low-power applications.

Orderable parts in the new LPC1500 seriesare the LPC1549, LPC1548 and LPC1547 withUSB, and the LPC1517, LPC1518 andLPC1519 without USB, in package versionswith 48, 64 or 100 leads.

New MCUs provide high-speed analogueperipherals and fast ARM core

APPLICATIONS• Motor control• Digital power supplies• Building automation• Data logging

FEATURES• Memory protection unit • Up to 256kbyte of on-chip Flash • Up to 36kbyte of SRAM• 4kbyte EEPROM• One 12-bit DAC• Configurable PWM, timer and motor-

control sub-system• Simple 18-channel DMA engine• Temperature range: -40°C to 105°C

SECURITYAUTOMOTIVEMEDICALLIGHTINGINDUSTRIALENERGY CONSUMER TELECOMMS

my-ftm.com/140302FOR PARTS ANDLATEST PRICING

FEATURES• 850V clamping voltage for 1ms• Planar-passivated for voltage ruggedness

and reliability• Pin-compatible with standard triacs



Apply at: my-boardclub.com

Motor-control and digital-powerapplicationsThe LPCXpresso board with NXP's LPC1549 ARMCortex-M3 microcontroller consists of a simplified Eclipse-based IDE and target boards which include an attachedJTAG debugger. LPCXpresso is an end-to-end solutionenabling embedded engineers to develop theirapplications from initial evaluation to final production.Orderable Part Number: OM13056

FREEBOARDS

NXP SEMICONDUCTORS

NXP Semiconductors has extended itsrange of ARM® Cortex™-M3 MCUs withthe new LPC1500 series, which offershigh computational capability and largeon-board Flash memory.

The new devices provide an unusually richchoice of high-performance analogueperipherals for embedded signal conditioning.These include two 12-channel, 12-bit ADCscapturing up to 2Msamples/s, four fastcomparators with an internal voltage reference,and four state-configurable timers, a peripheraltype that is unique to NXP.

These features make the LPC1500 seriesparticularly well suited to motor-control anddigital-power applications, in which it can offer<1ns PWM resolution and perform analogue-to-digital conversions in just 400ns.

The LPC1500 parts operate at frequencies ofup to 72MHz. The ARM Cortex-M3 CPUincorporates a three-stage pipeline and uses aHarvard architecture with separate localinstruction and data buses as well as a thirdbus for peripherals.

For industrial applications, the LPC1500integrates an on-chip C_CAN controller with adedicated programming interface stored in ROM.Some parts are also equipped with a Full-SpeedUSB2.0 device controller with on-chip PHY.

which require the ability to safely withstand highover-voltages, or which require compliance withthe IEC 61000-4-5 standard. These mayinclude AC fan, pump and compressor controls,highly inductive and resistive loads, whitegoods, and reversing induction motor controls.

The devices are also notable for their highminimum gate current, which gives themguaranteed immunity to gate noise.

Intersil’s Signal Path Kit: page 20ROHM’s ML610Q793: page 13STMicro’s LISxDH: page 17

PARTNERWORKING

C O M P O N E N T F O C U S

3V I S I T T H E O N L I N E F T M M A G A Z I N E A T: W W W . M Y - F T M . C O M

DC-DC converters combine high isolation and wideoperating temperature range

CUI PEM series: up to 89% efficient

IR389x buck regulators: fast response to voltage transients

CUI INC

CUI Inc., has introduced a family of low-power board-mounted DC-DC convertersfor use in harsh environments anddemanding applications.

The unregulated PEM series provides 3,000VDC of I/O isolation and a wide operatingtemperature range of -40°C to 105°C. Thereare two ranges of converters in the family:the PEM1-S devices are rated for a 1Woutput, and the PEM2-S for a 2W output.

CUI also produces the PES1-M, asurface-mount DC-DC converter whichprovides an isolated 1W output.

The PEM and PES series incorporate anumber of design and manufacturingimprovements to previous generations ofconverters, providing for improved efficiencyand thermal performance. Overall efficiencyhas been raised to as much as 89% at fullload. The new design also enhances thedevices’ performance across the load curve,reducing power consumption at light-loadand no-load conditions, making these

To provide an additional layer of protection forsensitive loads, the converters also come withcontinuous short-circuit protection and 8kV ofESD protection.

4A/6A dual-output voltage regulators occupy small board footprintINTERNATIONAL RECTIFIER

The new IR3891 and IR3892 SupIRBuck®

dual-output voltage regulators fromInternational Rectifier are aimed atspace-constrained designs which benefitfrom noise-free step-down regulation.

The new devices are optimised for single-railoperation from 5-12V inputs, or a 1-21V inputwith an external 5V bias. Available in a 5mm x6mm PQFN package, the regulators canprovide up to 4A per channel (IR3891) or 6Aper channel (IR3892) in a board footprint assmall as 165mm2.

The IR3891 and IR3892 feature aproprietary modulation scheme that providesfor jitter-free and noise-free operation. Thisenables the system to operate at high frequencyand high bandwidth for better transientresponse. It also means that the power systemdesign needs fewer output capacitors, helpingto reduce the space it occupies.

Single-sided PCB designs using the IR3892 are46% smaller than traditional designs using two6A, single-output converters. The IR3892 alsoworks comfortably with dual-sided designs,reducing PCB board size to less than 30% ofthe space required in traditional designs.

The IR3891 and IR3892 also share featuresthat are common to the whole SupIRBuckfamily, including pre-biased start-up, inputvoltage awareness, over-voltage protection,power-good monitoring, optional true outputvoltage sensing and internal soft-start. Like therest of the SupIRBuck family, the two newdevices are qualified for industrial applications.

APPLICATIONS• Medical equipment• Industrial control equipment• Mixed-signal systems• Security equipment

FEATURES• Typical efficiency:

• PEM1-S = 79% – 81%• PEM2-S = 84% – 89%• PES1-M = 80% – 81%

• 300kHz maximum switching frequency at full load

• 1,000MΩ isolation resistance at 500V• 3,500,000 hours mean time before failure



APPLICATIONS• Distributed point-of-load architectures• Telecoms equipment• Set-top boxes• General DC-DC converters

FEATURES• Interleaved phases reduce input capacitance• Powertrain isolation eliminates crosstalk• Sequencing capability on Channel Two• Precise reference voltage• Operating junction temperature range:

-40°C to 125°C




Voltage regulationInternational Rectifier provides reference design kits forthe IR3891 and IR3892, demonstrating implementationsof an integrated point-of-load DC-DC voltage regulator. Orderable Part Numbers: IRDC3891 and IRDC3892

FREEBOARDS

Part Number Output Current Switching Frequency (kHz) Package Input Voltage Range

OutputVoltage Range

IR3891MTRPBF 4A/Ch 300-1,500 PQFN5mm x 6mm 1V – 21V 0.5V to 86% of

input voltageIR3892MTRPBF 6A/Ch 300-1,000

converters ideal for use in mobile and battery-powered devices.

The PEM converters are housed in a compact,industry-standard seven-pin SIP packagemeasuring 19.6mm x 7mm x 10mm, and thePES1-M in an eight-pin package measuring12.7mm x 8.3mm x 7.25mm. The PEM seriesoffers nominal inputs of 3.3V, 5V, 12V, 15V and24V (±10%) and output voltage configurations of3.3V, 5V, 9V, 12V, 15V, 24V, ±5V, ±12V, ±15V,and ±24V. The PES series offers inputs andoutputs from 5V to 24V or ±5V to ±24V.



Miniature transient voltage suppressors tolerate200W power pulses

The Littelfuse SMF series responds to transient voltages in lessthan 1ns

LITTELFUSE

Littelfuse has introduced the new low-profile SMF series of Transient VoltageSuppressors (TVS) which protectsensitive electronic equipment fromspikes induced by lightning, and othertransient voltage events.

The surface-mounted SMF package of thenew devices has a footprint half the size ofTVS products in the SMA package. At just1.1mm high, the new TVS devices provide anexcellent fit for the latest generation of thinconsumer and computing devices.

The SMF series satisfies the requirements ofIEC 61000-4-2 (IEC 801-2) for the ESDprotection of data lines, withstanding 8kV(contact) and 15kV (air) peak voltages. Thepeak transient power tolerance of 200W isspecified for a 10x1,000µs waveform, at aduty cycle of 0.01%.

The devices also respond extremely quickly totransient events, typically taking less than 1nsto go from 0V to their minimum breakdownvoltage. They are also notable for their lowinductance and excellent clamping capability. APPLICATIONS

• Protection of I/O interfaces• Protection of supply rails

FEATURES• Compatible with standard SOD-123

package • Typical failure mode: short from over-

specified voltage or current • Built-in strain relief • Glass-passivated junction • 100°C/W thermal resistance, junction

to lead



Buck regulator enables space-saving 5A power-supply designs

SiP12108: high switching frequency enables use of small output inductor

VISHAY

Vishay has extended its microBUCK®

family of synchronous buck regulatorswith a new device that enables thedesign of circuits supplying a 5Acontinuous output in a tiny 180mm2

footprint.

The Vishay Siliconix SiP12108, which includeshigh- and low-side power MOSFETs, ishoused in a miniature 3mm x3mm QFN-16 package. Itfeatures programmableswitching frequencies of up to4MHz, enabling the use of avery small output inductor andother supporting components.

The device has a selectablepower-saving mode in which itoffers efficiency of 95% acrossthe entire load-current range.Its current-mode constant on-time regulation schemedelivers fast transient responsewith minimum outputcapacitance and tight rippleregulation over the entire loadrange.

The SiP12108 offers an easy migration path todevices supporting higher currents, and is alsofootprint-compatible with the 3A SiP12107.Since the regulator is stable with any capacitortype and does not require an ESR network forloop stability, system designs using theSiP12108 are simpler than with manycomparable regulators.

Vishay's free PowerCAD online simulationtool provides designers with a fast andconvenient way to simulate and design circuitsusing the SiP12108.

APPLICATIONS• Point-of-load regulation • Space-constrained end-products • Power supplies for low-power processors,

DSPs, FPGAs and ASICs

FEATURES• Input voltage range: 2.8V to 5.5V • Output voltage range: 0.6V to 4.6V • ±1% voltage accuracy • Output under-voltage and over-voltage

protection • Thermal shut-down • Input under-voltage lock-out • Internal soft-start



STMicro’s STGW40V60DF: page 7Avago’s ACPL-33xJ: page 6PARTNERWORKING


ESD protection diodes protect NFC antennas

NXP ESD protection diodes: very stable capacitance

NXP SEMICONDUCTORS

NXP Semiconductors has announced a new series of diodes which protectNear Field Communication (NFC)antennas in mobile devices fromtransient voltages.

The PESD18VF1BL and PESD24VF1BL are18V and 24V bi-directional ESD protectiondiodes. Housed in a small, leadless DFN1006-2

package, 1.0mm x 0.6mm x 0.48mm, the new diodes can be accommodated in thecompact portable devices, such assmartphones, which commonly include anNFC interface.

In these products, the NFC antenna is oftenintegrated into the battery cover or the batteryitself, and is connected to the NFC transceivervia small contacts. These contacts are anentry point for ESD strikes, which arepotentially hazardous to the NFC controller IC.The new NXP protection diodes safeguard theNFC IC, providing protection specified by theIEC 61000-4-2 industry standard.

At the same time, they help to maintain theantenna circuit’s signal integrity, because thediode capacitance varies very little withchanges in the bias voltage. The combinationof a high ESD voltage rating with lowcapacitance variation provides the bestpossible protection for the NFC system.

APPLICATIONS• ESD protection for NFC antennas• ESD protection of high-speed data lines

FEATURES• 0.35pF capacitance • 10kV ESD rating (contact discharge)• 1nA reverse leakage current






Combined power module and gate driversupports BLDC designs

Microchip MCP8024: drives six external high- or low-side N-channel MOSFETs

MICROCHIP

Microchip has released a highlyintegrated power device for three-phase Brushless DC (BLDC) motors,combining a gate driver, a powermodule and a comprehensive set ofanalogue functions.

Operating across a wide voltage range of 6Vto 28V, the MCP8024 can drive six externalhigh- or low-side N-channel MOSFETs. On-board analogue features include:• three current-sensing

operational amplifiers• an over-current

comparator• a bi-directional

communications interface

In addition, the MCP8024provides an adjustablestep-down DC-DCconverter capable ofproducing 750mW,sufficient to power a motorcontrol system’smicrocontroller or digitalsignal controller. On-board5V and 12V LDOs are ratedfor a maximum 20mAoutput.

Designers can rely on the new device toprovide for robust operation, since it is capableof withstanding transient voltages of up to 48V.Offering a wide operating ambient temperaturerange of -40°C to 150°C, the MCP8024 canbe used in harsh environments such as theautomotive engine compartment.

Design flexibility is enhanced by theprovision of features useful to BLDC designs,including configurable driver dead-timemanagement, driver blanking-time control andan over-current limit for external MOSFETs.

The MCP8024 is available in thermally-enhanced 40-pin QFN 5mm x 5mm and 48-pinTQFP 7mm x 7mm packages.

APPLICATIONS• HVAC blowers and pumps• Fans• Motor control• Robotics

FEATURES• Peak output current: 0.5A at 12V• Shoot-through protection• Over-current and short-circuit protection• Internal bandgap reference• Two level translators



Integrated gate-drive optocouplersreduce system costs and board space

AVAGO TECHNOLOGIES

APPLICATIONS• Isolated IGBT/MOSFET inverter gate drive • Renewable energy inverters • AC and brushless DC motor drives • Industrial inverters for power supplies and

motor controls • Uninterruptible power supplies

FEATURES• 1,414V peak insulation voltage • 8.3mm creepage and clearance • 50kV/µs typical common-mode rejection • CSA, UL and IEC safety approvals




BLDC motor-drive applicationsThe MCP8024 TQFP BLDC motor driver evaluation boarddemonstrates Microchip’s MCP8024 in a BLDC motor-drive application. The board’s firmware uses a six-steptrapezoidal drive-control algorithm to demonstrate theMCP8024’s capabilities.Orderable Part Number: ADM00557

FREEBOARDS

The ACPL-336J provides a 2.5A, and theACPL-337J a 4A, rail-to-rail output capable ofdriving a high-power MOSFET or IGBT directly,improving overall power efficiency.

The highly integrated devices also include abuilt-in LED driver, active Miller clamp and ahigh desaturation blanking-current source.Integrated short-circuit protection and afeedback-control circuit for fault and under-

voltage lock-out conditions help to improvesystem reliability.

These integrated features reduce thenumber of discrete components andthe board space required by

designers to implement an isolatedgate-drive circuit.

The ACPL-337J andACPL-336Joptocouplersprovide an easy-to-use, compactand affordableisolated IGBTgate-drive solutionfor motor-control and power-inverter applications. The devicescan isolate, drive and protect IGBTsand MOSFETs while providingfeedback on their operational status.

Littelfuse’s SMF series: page 4STMicro’s STGW40V60DF: page 7PARTNERWORKING



Single-ended fan-out buffers provide up to 12outputs

ON Semiconductor’s fan-out buffers may also be used as leveltranslators

ON SEMICONDUCTOR

ON Semiconductor has introduced newfan-out buffers with multiple single-ended outputs.

The NB3F8L3010C and the NB3F8L3005Coperate on a 3.3V or a 2.5V supply, and allowthe voltages of the output signals to be set to3.3V, 2.5V, 1.8V or 1.5V, as long as the voltageon the output signals is less than or equal tothe supply voltage.

The outputs on each of these devices areseparated into two banks: the voltage on theoutput signals can be configured independentlyacross each bank allowing designers to easilymix on the same board chipsets which usedifferent supply voltages.

The devices can also be used as leveltranslators, since they allow the voltage of theoutput signals to be configured, providingmore flexibility in board design by removing theneed for external components to perform thevoltage translation. The devices also offer asynchronous Output Enable/Disable featurethat provides power savings when the outputsignals are not required.

The NB3F8L3010C has ten outputs, five in eachbank, whereas the NB3F8L3005C has fiveoutputs, two in bank A and three in bank B.Both devices are notable for their flexible inputstructure, and can be used as multiplexers.

ON Semiconductor has also recently releaseda third fan-out buffer. The NB3V8312C hasone single-ended LVCMOS/LVTTL input and12 single-ended LVCMOS/LVTTL outputs andcan accept signals up to 250MHz.

It can operate on a 3.3V, 2.5V or 1.8Vsupply and allows the voltages of the output

signals to be set to 3.3V, 2.5V or 1.8V, as longas the voltage on the output signals is lessthan or equal to the supply voltage.

APPLICATIONS• Ethernet switches and routers• SONET, Ethernet and Fibre Channel line

cards• Servers and storage area networks• Optical networks• Test and measurement equipment• Medical imaging• High-end audio and video

FEATURESNB3F8L3010C/NB3F8L3005C:

• Crystal input, 10MHz to 50MHz • Single-ended LVCMOS/LVTTL and

differential LVPECL, LVDS, HCSL & SSTLinputs up to 200MHz

• Outputs separated into two banks wherevoltage of output signals can beconfigured independently across each bank



600V IGBTs curb turn-off current tail

STGW40V60DF 600V IGBT: supports high switching frequencies

STMICROELECTRONICS

STMicroelectronics has added to its Vseries of 600V IGBTs with the 40ASTGW40V60DF, which enables thecreation of designs benefitting fromimproved system energy efficiency,higher switching frequencies and betterthermal and EMI characteristics.

The new device increases switching efficiencyand maximum operating frequency byeliminating the turn-off current tail found inconventional IGBTs. Turn-off switching lossesare rated at a typical 560µJ at 400V/40A, and175°C junction temperature. Under the sameconditions, typical turn-off delay time is just220ns.

In addition, advanced fabrication technologypermits the production of an ultra-thin die,which benefits the device’s switchingperformance and improves heat dissipation.

In fact, the use of ST’s proprietary trench-gate field-stop process in the STGW40V60DFprovides for excellent junction-to-case thermalresistance of 0.53°C/W, as well as support for

a maximum junction temperature of 175°C. Itis also the reason for the part’s tight controlover parameters such as saturation voltage,which allows safe paralleling of multiple IGBTsand enables greater current density and higheron-state efficiency.

A co-packaged soft-recovery diodeminimises turn-on energy losses. Diode-freevariants are also available for more cost-sensitive applications.

The 40A/600V STGW40V60DF is available in aTO-247 package. The part also comes in aD2PAK (STGB40V60DF) and a TO-220(STGP40V60DF) package.

APPLICATIONS• Photovoltaic inverters• Uninterruptible power supplies• Welding equipment• Power factor correction• Very high-frequency converters

FEATURES• 1.8V saturation voltage at 40A• 250nA maximum gate-emitter leakage

current at 20V• 226nC total gate charge• 52ns turn-on delay time



Littelfuse’s SMF series: page 4Avago’s ACPL-33xJ: page 6PARTNERWORKING



New chip capacitors offer industry’s lowestleakage current

Vishay’s TL3 chip capacitors are ideally suited to devices that require long battery run-time

VISHAY

A new series of TANTAMOUNT®

surface-mount tantalum chipcapacitors will appeal to power-conscious designers due to their very low leakagecurrent ratings.

The TL3 chip capacitors offerDC leakage current as low as0.005 CV or 0.25µA,whichever is greater. Thismeans for instance that, bysubstituting the TL3 forcapacitors with a higherleakage current, systemdesigners can extend batteryrun-time in portable devices.

The TL3 capacitors areoffered in a moulded packagein five standard EIA-535BAACcase codes: A, B, C, D and E.

They are also available in a standard option oran option providing low equivalent seriesresistance.

Vishay produces TL3 devices with capacitancevalues ranging from 0.1µF to 470µF and withvoltage ratings from 4V DC to 63V DC.Capacitance tolerance is either ±10% or ±20%.

Devices in case codes B, C, D and E are100% surge-current tested and offer highreliability of 0.5%/1,000 hours, making themideal for use in products with a long operatinglifetime.

APPLICATIONS• Battery-operated equipment• Portable instrumentation• Tyre pressure-monitoring systems • Medical instruments• Battery back-up power supplies

FEATURES• Qualified to EIA-717• 100% matte tin terminations




P.I.E.S E C T I O N


Relay rated to handle 320A in-rush currentTE CONNECTIVITY

APPLICATIONS• Lighting control systems• Motion sensors • Home automation • Electronic switches for fixed installations

FEATURES• Standard 5mm footprint• Reinforced insulation• VDE approved • UL recognised



Small connector system supports 5Amaximum current

DF64 connector features a side-locking structure which provides high retention force

HIROSE

Hirose has introduced the DF64 seriesof compact connectors suitable for usein LED lighting and power supplies.

The device is applicable to board-to-wirepower-supply connections and board-to-boardbridge connections.

APPLICATIONS• LED lighting• Automotive headlamps• Medical devices• Factory automation controllers • Power supplies

FEATURES• Contact positions: 2 and 3• 4.5mm pitch• Cable size range: AWG18 to AWG22



C O M P O N E N T F O C U S P.I.E.S E C T I O N

Only one type of receptacle is needed,irrespective of whether the cable plug orboard-mount plug is used, allowing areduction in the number of componentsneeded.

The connection system can handle amaximum current of 5A when using AWG18cable. The creepage distance is a minimum of3.2mm between the contacts, which providesfor a 350V rating.

The board-to-wire connector uses a unique,stress-free, side-locking structure whichprovides a high cable-pull retention force. Thelock gives a consistent and positive tactileclick on mating. This ensures the connector isfully engaged, guaranteeing complete electricaland mechanical connection.

In the mated position, the contacts touchtogether in two different areas, providing highcontact reliability.

The board-to-board bridge connector has afloating structure which provides a mountingtolerance of 0.5mm in the x axis and 2mm inthe y axis, a feature which helps to ease theinstallation process.

TE Connectivity has introduced a relaycapable of handling an in-rush currentas high as 320A, as specified by theIEC 60669-1 standard, for switches inhousehold and similar fixed electricalinstallations. The new RTX relay israted for continuous loads of up to16A/250V AC.

The high in-rush capability of this 1 form A(NO) relay is a feature of its innovative dual-contact system. It incorporates both a TE flip-flop spring and a tungsten pre-make contactset to switch in-rush currents up to 320A.Loads are carried and broken using the relay’ssilver tin oxide contact set.

An extension of the RT family of relays forhigh in-rush current, the RTX has a newlydesigned bi-stable magnetic system. Bothone- and two-coil models provide high energyefficiency. The relay’s actuator design alsofeatures a built-in contact-opening mechanismwhich helps to open microwelds occurringduring the operation of the relay, thusextending its life. TE’s RTX relay: half the size of

comparable relays from other manufacturers

Measuring only 29.1mm x 12.7mm x 16mm,the RTX is approximately half the size of otherproducts on the market, thus offering designersa means to save space while maintaining highin-rush current capability.

A N A L O G U E & S E N S I N G

Analogue and SensingLow power, miniaturisation and precision are the watchwords ofthis month’s Application Spotlight on analogue and sensing. In some cases, familiar device types

have benefitted from incrementalimprovements to their circuit design andfabrication process. Intersil’s 5Vinstrumentation amplifiers, on page 12, forexample, offer improved precision thanksto circuitry that provides automatic offset-voltage correction and noise reduction. Likewise, new Nanopower op amps and

comparators from STMicroelectronics, onpage 18 and 20, provide welcomereductions in supply current compared toexisting products on the market. But analogue IC manufacturers are

innovating in big ways as well. ST isparticularly notable for its massivedevelopment efforts in the field of MEMS,creating both the intellectual property to enable its designs, andthe fabrication capability to make the devices.

It is MEMS technology that enables the production of devicessuch as ST’s iNEMO-M1, on this page, an amazingly small 9-axis

sensor module measuring acceleration,angular rate and direction of motion.Widely used in smartphones andtablets, MEMS sensors are findingmany new uses as OEMs experimentwith their capabilities in applicationssuch as personal navigation, virtualreality and gaming. In a different arena, ams has

developed a new approach to themonitoring of cells in large lithiumbatteries, on page 15. It has found away to implement cell monitoring andbalancing without the need for an MCUand sensitive communications links.This provides for better performanceand a smaller bill-of-materials.

This and all the other innovations in analogue and sensing arefeatured in the pages of this Application Spotlight.


APPLICATIONS• Gesture recognition• Robotics and inertial body tracking• Augmented/virtual reality• Human-machine interfaces• Gaming • Sports and wellness equipment

FEATURES• 28-pin 13mm x 13mm x 2mm board• Up to 8 ADC channels for external inputs• Ceramic resonator



System-on-board provides 9-axis sensing withdistributed intelligence

9-axis sensor module also includes powerful ARM Cortex-M3 MCU

STMICROELECTRONICS

The iNEMO-M1, an STMicroelectronics9-axis sensor system, combines agyroscope, accelerometer andmagnetometer with a powerful 32-bitmicrocontroller and a low-noise voltageregulator on a single miniature board.

The iNEMO-M1 platform provides a flexiblemeans for designers to implement 9-axismeasurement while benefitting from low powerconsumption and low cost.

The iNEMO-M1 includes the 3-axis L3GD20digital gyroscope, the 6-axis LSM303DLHCdigital e-compass module, combining anaccelerometer and magnetometer, and theSTM32F103REY6 ARM® Cortex™-M3 32-bitmicrocontroller. The iNEMO-M1 draws on thewide set of peripherals supported by the MCU tooffer the designer flexibility in communication.Serial interfaces available include CAN, USART,SPI and I2C. It also offers a Full-Speed USB2.0interface.

The iNEMO-M1 can operate with an externallyregulated 2.4-3.6V power supply or, by usingthe on-board LDS3985M33R voltage regulator,it may be supplied by an external voltage inthe range of 3.6V to 6V.

When integrated into a motion-sensing system,the iNEMO-M1 helps to simplify system designand improve overall performance by distributingsystem intelligence. Designers can also useST’s iNEMO sensor fusion software suite, a setof adaptive prediction and filtering algorithms,to make sense of the complex informationderived from multiple sensing devices.

The software suite includes two productlines: iNEMO Engine Lite, a free softwarelibrary for motion-detection system evaluation,and iNEMO Engine Pro, a compiled softwarelibrary with data-fusion algorithms for processingmultiple sensor outputs. The iNEMO engine iscompatible with all ST MEMS sensors.


9-axis sensingThe iNEMO-M1 Discovery kit provides a 35mm x 35mmboard which includes both the iNEMO-M1 9-axis system-on-board and the LPS331AP integrated pressure sensor.It also includes a USB connector, an SWD connector fordebugging and programming, an external power-supplyconnector and extension headers for access to theiNEMO-M1’s pins.Orderable Part Number: STEVAL-MKI121V1

FREEBOARDS



High-precision applicationsThe ISL2853x_63xEV2Z boards include all necessarycomponents to easily connect the high-performanceIntersil amplifier to an external signal.Orderable Part Number: ISL28533EV2Z

FREEBOARDS


High-precision applicationsThe STEVAL-MKI142V1 is an adapter board for evaluatingthe LPS25H MEMS pressure sensor. It can be pluggedinto a standard DIL 24 socket. The adapter providesaccess to the complete LPS25H pin-out and comesready-to-use with the required decoupling capacitors onthe power-supply line.Orderable Part Number: STEVAL-MKI142V1

FREEBOARDS

Temperature drift close to zero innew instrumentation amps

New Intersil programmable-gain instrumentation amplifiers offer stable and precise performance

INTERSIL

Intersil has released a family of 5Vzero-drift programmable-gaininstrumentation amplifiers which areideal for high-precision applicationsover a wide temperature range.

The ISL2853x and ISL2863x family ofinstrumentation amplifiers are notable for theirlow offset, low noise, low gain error and highCommon-Mode Rejection Ratio (CMRR).

The devices areequipped with a 2-bit, 3-state logic interfacethat provides for up tonine selectable gainsettings between 1 and1,000.

The ISL2853xdevices provide asingle-ended outputwhich includes anadditional, uncommittedzero-drift amplifier.

This may be used to buffer the Referenceinput or as a precision amplifier. The ISL2863xdevices provide a differential output whichincludes a Reference pin to set the common-mode output voltage, so that the amplifier caninterface to differential-input ADCs.

All the amplifiers feature zero-drift circuitrythat provides automatic offset-voltage correctionand noise reduction. With a very low offsetvoltage drift of 5nV/°C, the output of theamplifiers is extremely stable over the entireoperating temperature range of -40°C to 125°C.

In addition, the amplifiers feature a low,<1Hz 1/F noise frequency corner.

Miniature barometer offers lownoise and high precision

STMICROELECTRONICS

The LPS25H from STMicroelectronicsis tiny piezo-resistive pressure sensorwhich integrates both a monolithicsensing element and a digital interfaceto the outside world.

Its pressure measurement range of 260mbarto 1,260mbar enables it to operate as abarometer in a range from10,000m above sea level(higher than Everest’s peak)to 1,800m below sea level.

The high precision of theLPS25H allows the user todetect a change in altitude ofas little as 20cm. It is accurateto ±0.1mbar, over the range800-1,100mbar, and noise isspecified at just 0.025mbar inhigh-resolution mode.

Calibrated at threetemperatures and twopressures for better sensitivityand accuracy, the LPS25H

requires no external compensation software tocorrect measurement errors. In addition,power consumption is extremely low: even inhigh-resolution mode it draws a maximum ofjust 25µA.

The LPS25H is housed in a 2.5mm x2.5mm LGA-10 package which has a hole toallow pressure from the outside to act on themicro-machined sensing membrane. Anintrinsic mechanical stopper prevents themembrane from breaking when exposed toexcessive pressure.

12 F R E E D E V E L O P M E N T K I T S A T W W W . M Y - B O A R D C L U B . C O M

APPLICATIONS• Indoor and outdoor navigation• Altimeter/barometer in portable devices• GPS equipment• Sport watches• Weather stations

FEATURES• Pressure sensitivity: 4096LSB/mbar• 0.5µA quiescent current• Selectable output data rate: 1-25Hz• 24-bit data output• Survives 10,000g shocks• SPI and I2C interfaces



APPLICATIONS• Pressure and strain-gauge transducers• Weighing scales and flow sensors• ECG/blood glucose meters• Temperature sensors• Test and measurement equipment• Data-acquisition systems• Low ohmic current sensing

FEATURES• Rail-to-rail input/output• 5µV maximum input offset• 138dB CMRR, at a gain of 100• <0.4% maximum gain error • 2.3MHz gain bandwidth




8-bit MCU with multiple interfaces operates assensor hub controller

ROHM SEMICONDUCTOR

The ML610Q793 from LAPISSemiconductor, a division of ROHMSemiconductor, is a high-performance8-bit microcontroller for controllingsensor hubs.

The device is based onLAPIS Semiconductor’s8-bit CPU core. Inaddition to this, it isequipped with a 16-bitco-processor whichimplements multiplication,division, and multiply-accumulate operations,as well as Flash andSRAM memories, andmultiple interfaces tovarious sensor types.

The ML610Q793 cantherefore be used incomplex systems torelieve an applicationprocessor of the burdenof controlling multiplesensors. This helps to

reduce system power consumption, andsimplifies system design, since a singlechannel between the ML610Q793 and anapplications processor can replace multiplechannels between sensors and applicationsprocessor.

The ML610Q793 is packaged in a 3.1mm x3.0mm WL-CSP.

Single IC controls up to 36 capacitive switchesROHM SEMICONDUCTOR

ROHM has introduced three newcontrollers for multiple capacitiveswitches, ideal for replacingmechanical switches with sleeker andmore reliable touch interfaces.

The BU21072MUV, BU21078MUV andBU21079F capacitive sensor controllersintegrate all the functions required to detectTouch, Release and Hold operations incapacitive touch sensors. The controller ICsinclude an analogue front-end for detectingcapacitance changes at the switches, an ADC,a processor core and a 2-wire I2C interface.

The BU21072MUV and BU21078MUV alsooffer a PWM function which provides for fade-in/fade-out control of indicator LEDs’brightness.

If the BU2107x device detects externalnoise or temperature drift, it runs an automaticself-calibration process.

When no touch is detected, the devicesenter an intermittent sensing mode whichconsumes less power than normal operation.

The controllers may be configured either assimple-switch or matrix-switch controllers. TheBU21072MUV and BU21079F support 16matrix switches configured as 4 x 4 sensors,and the BU21078MUV supports 36 matrixswitches configured as 6 x 6 sensors.


APPLICATIONS• Sensor hubs interfacing to an

applications processor

FEATURES• 64kbyte of Flash • 4kbyte of SRAM • Serial peripheral interface • I2C interface • UART interface • Serial I/O interface • 12-bit, 3-channel SAR ADC• Current requirement at 4.096MHz:

0.93mA• Current requirement in low-power mode:

0.6µA• Ambient operating temperature:

-30°C to 85°C



APPLICATIONS• Appliances that require multiple switches• Information appliances• Digital TVs • HDD recorders

FEATURES• Scan interval:

• 16ms (BU21072 and BU21078)• 6ms (BU21079)

• Power-on reset • Oscillator



NXP’s LPC1500: page 2STMicro’s LISxDH: page 17Intersil’s Signal Path Kit: page 20

PARTNERWORKING

Part Number VCC(Min.)

VCC(Max.)

Sensor InputChannels

LED ControlChannels Interface Matrix

Key

OperatingTemperature

(Min.) °C

OperatingTemperature

(Max.) °CPackage

BU21072MUV 3 5.5 10 6 I2C 4 x 4 -20 85 VQFN024V4040BU21078MUV 3 5.5 12 8 I2C 6 x 6 -20 85 VQFN028V5050BU21079F 3 5.5 8 – I2C 4 x 4 -25 85 SOP16



9-axis movement/position sensor offers new space savings

LSM9DS1 motion sensor supports devices used for indoor navigation

STMICROELECTRONICS

STMicroelectronics has revealed a new,more advanced module for 9-axismovement and position sensing thatoffers improved performance and lowerpower consumption.

The 3.5mm x 3mm LSM9DS1 is almost 35%smaller than previous generations of 9-axismodules. At the same time, the module has30% higher magnetometer resolution, due tothe use of ST’s latest low-noise process technology, aswell as 20% lower overallpower consumption. Theprecise position and motioninformation that the newdevice produces can providethe context awareness neededfor functions such as gesturecontrol, indoor navigation andaugmented reality.

The LSM9DS1 contains a 3-axis accelerometer, 3-axisgyroscope and 3-axismagnetometer, all fabricatedusing ST’s latest MEMS

process technology. These sensors detectlinear acceleration, angular rate and magneticfield to provide complete position- andmovement-sensing data.

Compatible with ST’s LSM6 family of 6-axisinertial measurement units, the LSM9DS1offers a simple upgrade path, allowingdesigners to add magnetic-field detection forfunctions such as e-compass and orientationsensing. Product developers can also upgradecurrent designs that combine a 6-axis LSM6device with a discrete magnetometer toachieve a smaller, simpler circuit based on theLSM9DS1.

New technology implemented in the LSM9DS1also delivers a significant reduction inaccelerometer zero-g offset, to less than100mg, and reduces typical gyroscope ratenoise to 0.008dps/√Hz at low full-scale.

SiP combines accelerometer and magnetometerin one compact unit

LSM303D: combination of magnetometer and accelerometer for digital compass

STMICROELECTRONICS

The LSM303D is a System-in-Package(SiP) which includes a 3-axis digitallinear acceleration sensor and a 3-axisdigital magnetometer.

The device offers linear-acceleration full scales of±2g /±4g /±6g /±8g /±16gand magnetic-field fullscales of ±2/±4/±8/±12gauss. Its digital outputsmay be provided to a hostcontroller via an I2Cinterface which supportsStandard and Fast Mode,100kHz and 400kHz, orvia a serial peripheralinterface.

The LSM303D includesan on-board FIFO whichholds acceleration data foreach of the three outputchannels.

This saves system power, as the host processordoes not need to continuously poll data fromthe sensor, but can wake-up only when neededto burst the significant data out of the FIFO.For further power savings, the magnetometerand accelerometer blocks can be enabled orput into power-down mode separately.

The LSM303D can be configured togenerate an interrupt signal for free-fall,motion-detection and magnetic-field detection.

The thresholds and timing of the interruptgenerators are programmable by the designer.

The LSM303D is available in a plastic LGA-16package, measuring 3mm x 3mm x 1mm, andis rated for operation over a temperature rangeof -40°C to 85°C.

APPLICATIONS• Tilt-compensated compasses• Map rotation• Position detection• Motion-activated functions• Free-fall detection• Pedometers• Display orientation• Vibration monitoring and compensation

FEATURES• 16-bit data output• Analogue supply voltage: 2.16V to 3.6V• Embedded temperature sensor



APPLICATIONS• Portable consumer electronics devices• Wearable electronics devices• Smart TV remote controls• Game controllers

FEATURES• 2mA operating current• 16-bit data output• SPI/I2C serial interfaces• Programmable interrupt generators• Embedded temperature sensor• Embedded FIFO



Vishay’s 34 THE: page 19PARTNERWORKING


Voltage-monitor IC offers simplerlithium-cell supervision and balancing

AMS

ams has introduced a simpler andmore robust method of implementingcell monitoring and balancing in lithiumbattery systems.

The innovative architecture developed by amscan be implemented with a new, highlyintegrated chip, the AS8506. This devicemonitors the voltage of individual cells andperforms balancing operations and SafeOperating Area (SOA) checks for stacked cellmodules. A single AS8506 can monitor up toseven lithium cells. Multiple AS8506 ICs maybe daisy-chained, enabling the monitoring ofbattery packs containing up to 32 modules ofseven cells, 224 cells in total.

The AS8506 is ideal for all lithium-based cellchemistries, such as those found in hybrid andfully electric vehicles, as well as forsupercapacitors.

In conventional systems, a complicatedalgorithm running remotely on a high-endmicrocontroller decides which cells have to bebalanced. The new architecture supported bythe AS8506 can control balancing locally at

the cells, enablingdesigners toimplement a morestreamlined cellmanagementsystem thateliminates thepowerful hostcontroller, complexsoftware and

vulnerable serial communication links normallyused today.

The AS8506 can implement both passiveand active cell balancing autonomously, or itcan support a microcontroller-based systemvia its serial peripheral interface. An analoguecircuit in the AS8506 compares each cell’svoltage against an internal or externalreference with an accuracy of ±1mV. Cellvoltage measurements can also be digitisedwith an accuracy of 5mV and reported to ahost controller.

The device also features internally orexternally adjustable upper and lower cell-voltage limits. When a cell’s voltage crossesthe upper or lower threshold, a warning signalwill be transmitted to a host controller.Temperature measurement is implementedwith two external sensors.

APPLICATIONS• Hybrid and fully electric vehicles• E-bikes and pedelecs• Power tools• Off-grid energy storage

FEATURES• PWM driver• 50mA LDO• Precision bandgap reference• Weak-cell detection logic





Cell monitoring and balancingThe AS8506 Standalone Balancer Kit demonstrates theAS8506’s ability to operate without a microcontroller andfirmware. It supports autonomous balancing of up toseven cells. The hardware will support lithium-based cellpacks as well as supercapacitors. The number of cells,target voltage and over- and under-voltages can beconfigured with resistor options.Orderable Part Number: AS8506-DK-ST

FREEBOARDS



Micropower Hall switches offerhigh magnetic sensitivity

Hall-effect switches: ideal for detecting open/close operation of doors and lids

DIODES INCORPORATED

Diodes Incorporated has extended itsfamily of Hall-effect switches with theintroduction of a pair of high-sensitivity,ultra low-power devices.The tiny AH1902 andAH1903 also offerdesign flexibility and theopportunity to saveboard space.

The AH1902 is an omnipolardevice, detecting both northand south poles. In itsdefault mode, theprogrammable AH1903operates as a unipolardevice, detecting a southpole at the part marked‘package surface’. Thedevice also offers anomnipolar mode, enabling itto meet the needs of multipleapplications and to be

changed on the fly if necessary. The AH1903’sfunction may be changed via a simple Selectpin driven by an external logic source ormicrocontroller.

The high sensitivity of both switches meansrelatively weak magnets can be used ordetection distances lengthened.

Rated for a typical operating current of 4.3µAand featuring an integral low-power Sleepfunction, the AH1902 and AH1903 are goodperformers in battery-powered applications.

The omnipolar AH1902 is available inDFN1216-4, ultra-thin DFN2015-6 andSOT553 packages. The AH1903, in a 1.2mmx 1.6mm x 0.5mm DFN1216-4 package, is theindustry’s smallest omnipolar/unipolarprogrammable Hall switch.

Transmissive optical sensors suitable for harshautomotive conditions

Transmissive sensors may be used in optical position sensors

VISHAY

Vishay has introduced two surface-mount transmissive optical sensorssuitable for harsh low- and high-temperature environments. The single-channel TCPT1350X01 and the dual-channel TCUT1350X01 are rated for awide operating temperature range of -40°C to 125°C.

The TCPT1350X01 includes aninfra-red emitter and a photo-transistor detector located face-to-face in a surface-mountpackage. The TCUT1350X01 hasthe same configuration, exceptthat it features two photo-transistor detectors rather thanone. The sensors have a photo-transistor output, apertures of 0.3mm, and operate at awavelength of 950nm.

The 3mm gap between theemitter and detector allows the

devices to be used with a wide variety ofmaterials, and also supports looser mechanicaltolerances than sensors with smaller gaps.This can be helpful in automotive and industrialapplications.

In particular, the TCPT1350X01 andTCUT1350X01 can be used as position sensorsfor encoders in high-temperature environmentsclose to motors, as well as in ignition locksand adaptive headlights.

Both sensors can detect motion and speed.The TCUT1350X01’s dual-channel outputmeans that it can also be used to detectdirection of motion in applications such aselectronic power steering.

APPLICATIONS• Door, lid and tray position switches • Level and proximity switches • Contactless switches in home appliances • Industrial applications

FEATURES• Supply voltage: 1.6V to 3.6V • High temperature stability • Minimal switch-point drift • Good RF noise immunity • 8kV ESD capability



APPLICATIONS• Automotive optical sensing• Position sensing in encoders• Speed measurement

FEATURES• AEC-Q101 qualified• 1.6mA output current• 5.5mm x 4mm x 4mm package• Moisture sensitivity level 1• 0.8mm channel distance (centre to centre,

TCUT1350X01 only)




17 V I S I T T H E O N L I N E F T M M A G A Z I N E A T: W W W . M Y - F T M . C O M

High-performance single-chip magnetometer

Tiny LIS3MDL magnetometer suited to compact, portable consumer electronics devices

STMICROELECTRONICS

STMicroelectronics has added to itsMEMS sensor portfolio with theLIS3MDL, a high-performance, stand-alone 3-axis magnetometer.

The LIS3MDL is perfectly suited to indoor-navigation applications, in which it reliablycalculates position through dead reckoningwhen no satellite signal is available. Non-linearity is rated at a typical±0.12% of full scale.

Measuring just 2mm x2mm x 1mm, the LIS3MDLmagnetometer may readilybe combined with discreteMEMS sensors such as a3-axis accelerometer or 3-axis gyroscope, to buildsensors measuring acrosssix or nine axes.

Using ST’s iNEMOEngine sensor-fusionsoftware, designers can co-ordinate any combination ofsensors from ST’s broadportfolio to create reliable,

high-quality multi-axis systems. For example,combining a MEMS pressure sensor, tomeasure altitude, with the LIS3MDL positionsensor can enhance the accuracy of in-buildingnavigation.

The LIS3MDL offers user-selectable full-scalesof ±4/±8/±12/±16 gauss. To link to a hostcontroller, the device has an I2C interface whichsupports Standard and Fast mode, 100kHzand 400kHz, and a serial peripheral interface.

Sensor detects extreme shocks up to 400g in 3D

Measuring shocks up to 400g, the H3LIS331D is finding uses in high-impact sports

STMICROELECTRONICS

STMicroelectronics has unveiled theworld’s first motion sensor to measureacceleration up to 400g in threedimensions, while consuming very littlepower.

Existing high-g shock-detection designs aremostly based on single-or dual-axis airbag-typesensors: these arepower-hungry, and lackprecision because theydo not sense along allthree axes. By contrast,ST’s new H3LIS331D is a3-axis accelerometerwhich is suitable forbattery-operatedapplications, drawing aslittle as 10µA in low-power mode.

Non-linearity is rated ata typical 2% of full scale,measuring up to ±100g.

Sensitivity is a typical 195mg/digit across thefull scale of ±400g.

By offering precise, low-power measurementof extreme shocks, the H3LIS331D opens newpossibilities for portable medicalinstrumentation and concussion monitoring inhigh-impact sports such as ice hockey,American football and motor racing. ST’s high-gsensors can also improve the crash-detectioncapabilities of event data recorders (black

boxes) and freight monitoring systems, as wellas enhance anti-shock protection in consumerelectronics products.

The H3LIS331D provides excellent stabilityover time and temperature. An on-chip ICinterface converts the acceleration data into a16-bit digital bit-stream which is transmittedwith high reliability to a host controller througha standard SPI or I2C protocol.

APPLICATIONS• Magnetometer• Compass

FEATURES• Supply voltage range: 1.9V to 3.6V• Continuous and single-conversion modes• 16-bit data output• Interrupt generator



APPLICATIONS• Shock detection• Impact recognition and logging• Concussion detection

FEATURES• ±100g/±200g/±400g dynamically

selectable full scale• Sleep-to-Wake-up function• Capable of surviving 10,000g shock



NXP’s LPC1500: page 2ROHM’s ML610Q793: page 13Intersil’s Signal Path Kit: page 20

PARTNERWORKING


3-axis magnetometer applicationsThe STEVAL-MKI137V1 adapter board for the LIS3MDLcan be plugged into a standard DIL 24 socket. Theadapter provides access to all the LIS3MDL’s pins, andcomes ready-to-use with the required decouplingcapacitors on the power-supply line. The adapter board iscompatible with the STEVAL-MKI109V2 motherboard.Orderable Part Number: STEVAL-MKI137V1

FREEBOARDS



Nanopower 5V CMOS amplifiershelp prolong battery life

TSU series of op amps offers stable specifications across a wide voltage range

STMICROELECTRONICS

STMicroelectronics has introduced theTSU series of Nanopower operationalamplifiers offering ultra-low powerconsumption, ideal for battery-poweredapplications required to run for verylong periods without recharging.

The TSU101, TSU102 and TSU104 draw amaximum 750nA current (580nA typical) whenoperating from a 1.8V supply. The input biascurrent is a low 5pA maximum at 25°C.Offering stable operating specifications acrossa wide supply voltage range of 1.5-5.5V, theTSU101/2/4 gives the designer a highlyefficient choice for circuits that run from alithium coin cell or from a regulated voltage inlow-power applications.

Featuring a typical gain bandwidth productof 8kHz, this device is ideal for sensor signalconditioning, and may be used reliably acrossa temperature range of -40°C to 85°C.

High speed and low drift the hallmarks of newprogrammable current sensor

MELEXIS Housed in a standard SO-8 package, theseICs give engineers the means to implement acompact current-sensing design which benefitsfrom strong galvanic isolation.

APPLICATIONS• Electric and hybrid-electric vehicles• Current monitoring in BLDC motors• Smart fuses• AC-DC converters • Inverters• DC-DC switch-mode power supplies

FEATURES• Selectable analogue ratiometric output • Noise filter



APPLICATIONS• Energy-harvesting systems• Personal medical monitors• Battery current sensors• Smoke alarms• PIR detectors• Wireless sensors• Security cameras• Smart tags

FEATURES• Unity gain stable• Rail-to-rail input and output• 2kV (Human Body Model) tolerance to ESD



Melexis has expanded its Triaxis® Hall-effect sensor IC range with the high-speed MLX91208 series ofprogrammable current sensors.

Offering a fast response time ofjust 3µs, the MLX91208 devicesfeature design elements thatprovide stable accuracy overboth lifespan andtemperature. Typicaltemperature drift is±150ppm/°C.

The transfer characteristicsof the MLX91208 devices arefully adjustable by thedesigner: parameters such assensitivity, gain and offset maybe stored on the built-in EEPROM.Calibration is performed with Melexis’Programming Through Connector protocol.This eliminates the need for an additional pin

for programming and thus streamlines end-product production.

The MLX91208 devices are well suited toprecision DC measurement, and measurementof AC at frequencies of up to 200kHz. Thesensors are notable for their high sensitivity,which stems from an Integrated Magnetic

Concentrator (IMC) layerdeposited on the die. There

are two versions ofthe MLX91208: theMLX91208CAL hasa larger IMC layer,enabling it to detectvery weak magneticfields of 100mV/mTto 700mV/mT. TheMLX91208CAH issuitable for thedetection of

medium-strength fieldsof 50mV/mT to 300mV/mT.

Current-sensing systems usingthe MLX91208 series may be expected to

offer accuracy of better than ±0.5% at roomtemperature, and of ±2% across the whole ofthe specified temperature range.

Package Options and Part Numbers

TSU101ICT SC70-5TSU101ILT SOT23-5TSU101RICT SC70-5TSU101RILT SOT23-5TSU102IQ2T DFN8 2x2TSU102IST MiniSO8TSU104IQ4T QFN16 3x3TSU104IPT TSSOP14



Rotary position sensor offers accuracy and long life

34 THE rotary position sensors: choice of analogue, PWM and SPI outputs

VISHAY

The 34 THE from Vishay is a Hall-effectrotary position sensor that can measurecontinuous angular displacement up toten turns (3,600°). Produced in an 09size, 22.2mm diameter housing, itaccepts either servo or bushing mounts.

The contactless Hall-effect technology used forangle measurement in the 34 THE endows itwith outstanding resistance to environmentalconditions. It is rated for operation under theeffect of high-frequency vibrations up to 20G,and of shocks up to 50G.

At the same time, it offers a very long life of50 million cycles with a servo mount and 10million cycles with a bushing mount, which is atleast ten times longer than typical wirewoundmulti-turn sensors.

Accurate to ±0.5%, the 34 THE may bespecified with either single or redundant signals.It produces an analogue, PWM or SPI output,and maintains stable linearity throughout itslifetime.

A supply current of <16mA at 5V is sufficientfor the single-signal version, and <32mA forredundant signals. The recommended loadresistance is 1kΩ for analogue and PWM outputs.

Digital temperature sensor combines wide range andhigh accuracy

NXP SEMICONDUCTORS

The device uses an on-chipband-gap temperature sensorand 11-bit sigma-delta ADC toprovide a digital temperaturereading with a resolution of0.125°C. It also provides an over-temperature detection output.

Over the temperature range -25°Cto 100°C, the LM75B is accurate to±2°C. Even over the maximumtemperature range of -55°C to 125°C,high accuracy of ±3°C is maintained.

The LM75B can be configured for variousoperating modes. In normal mode, itperiodically monitors the ambient temperature.In shut-down mode, the supply current falls tojust 1.0µA.

The device also includes an open-drain output,OS, which becomes active when thetemperature exceeds the programmed limits.The OS output operates in either of twoselectable modes: OS comparator mode or

OS interrupt mode. The LM75B includes threeselectable logic address pins

and I2C interface, so that asmany as eight devices may

be connected on thesame bus without

conflict.Since the I2C bus

block on the chip istotally independentof the ADC block,the LM75B may beaccessed withoutinterrupting theconversionprocess. This

means that accessingthe device continuously

without waiting at least oneconversion cycle between

communications will not prevent the devicefrom updating the temperature register with anew conversion result.

The device can store programmable over-temperature, shut-down and hysteresis limits,communicated by a controller via the I2Cinterface.

APPLICATIONS• Vehicles• Industrial equipment• Medical devices• Telecoms/datacoms equipment

FEATURES• Supports stand-alone operation as a

thermostat at power-up• Supply voltage: 2.8V to 5.5V• Pin-compatible with LM75 and LM75A

temperature sensors



APPLICATIONS• Servo control of steering wheels • Steering systems in boats• Position control for linear electrical

actuators

FEATURES• 1,200rpm maximum speed• +20V over-voltage protection • -10V reverse voltage protection• Anodised aluminium housing• Stainless-steel shaft



STMicro’s LSM9DS1: page 14PARTNERWORKING

The LM75B from NXP Semiconductorsis a temperature-to-digital converterwhich maintains very high accuracy over a wide temperature range.



Intersil provides enhanced sample kit to enableevaluation of signal-path products

TS88 series: no need for pull-up resistor

STMICROELECTRONICS

The TS88 series of Nanopowercomparators from STMicroelectronicscombine ultra-low power consumptionwith a typical response time of 2µs.

The TS881, TS882 and TS884 are single-,dual- and quad-output comparators. They arespecified for a typical supply current of 210nAper channel, with output High, supply voltage1.2V, no load.

Since they are capable of operating from asupply voltage as low as 1.1V, they keepsupply leakage current to extremely low levelsover a wide temperature range, enablinglonger operating times with smaller batteries.

Despite the TS88 parts’ extremely spare useof power, they are faster than competingdevices on the market, allowing a significantreduction in equipment response times.

Providing a push-pull output, use of theTS88 series avoids the need for a separatepull-up resistor.


APPLICATIONS• Alarm and monitoring systems • Portable medical equipment • IR receivers • Wireless security systems • Remote controls • Handheld instruments • Metering equipment• Telemetry

FEATURES• Rail-to-rail inputs • Supply voltage range: 1.1V to 5.5V • 8kV ESD tolerance (Human Body Model) • Operating temperature range:

-40°C to 125°C



NXP’s LPC1500: page 2ROHM’s ML610Q793: page 13STMicro’s LISxDH: page 17

PARTNERWORKING

Part Number Packages Number ofChannels

TS884SO-14

TSSOP-14VFQFPN 16 3 x 3 x 0.9

4

TS882MSOP/TSSOP-8

SO-8UFSON 8 2 x 2 x 0.6

2

TS881 SC70-5SOT23-5L 1

Low leakage and low operating current in new lineof comparators

Together, the samples in the pack can be usedto construct several different, complete signalchains. The samples are production itemswhich have been tested and are known good.

The parts are presented in a robust cardpackage containing summarised technicaldata about the sample parts and other Intersilproducts with similar specifications.

The SPP2 sample kit may be ordered directfrom any branch of Future Electronics.

INTERSIL

Intersil has released the latest versionof its sample kit of signal-pathproducts, named SPP2.

The latest sample kit provides three samplesof an Intersil part in each of the followingcategories: • RS-485 transceiver• Digital potentiometer• Analogue switch• Voltage reference• Instrumentation amplifier• High-speed amplifier• Real-time clock• Current-sense amplifier• Digital power monitor

It also includes three samples each of twoprecision amplifiers: the ISL28134 and theISL28217. The pack also features samples offour ADCs, from the single-channel ISL2671212-bit SAR ADC to the ISL26102, a dual-channel 24-bit delta-sigma ADC.

Future Electronics’ Board Club: supporting innovative electronics designEurope’s electronics industry thrives on the application of innovation and creativity, and an essentialinnovator’s tool in design projects is the development board. The Board Club website is a Future Electronicsresource for users of development boards. Here, and only here, Board Club members can gain access toexclusive free development boards and development board offers.If you would like to register for membership, please visit: www.my-boardclub.com/register.php

B O A R D O F T H E M O N T H

New LPC1500 development board hosts advancedLPCXpresso development softwareNXP Semiconductors’ new LPC1500development board, part numberOM13056, is compatible with theLPCXpresso™ low-cost developmentplatform, which supports NXP’s ARM®-based microcontrollers. The LPC1500,as featured on page 2, is the latestARM Cortex™-M3 microcontroller fromNXP and offers a combination of highcomputational capabilities and a richset of on-board analogue peripherals.

FEATURES• Fully supported by LPCXpresso Eclipse-

based IDE and GNU C/C++ toolchain,available in free and Pro versions

• Integrated JTAG debugger which can alsobe used to debug external targets

• LPCXpresso/mbed, PMOD and ArduinoUNO expansion connectors give accessto a wide range of expansion boards

• Tri-colour LED, ISP and WAKE buttons foreasy testing of software functionality



The LPC1500 development board, whichsupports LPCXpresso, a simplified Eclipse-based Integrated Development Environment(IDE), is supplied with an attached JTAGdebugger board. The LPCXpresso platform isan end-to-end solution enabling embeddedengineers to develop their applications frominitial evaluation to final production. The latest LPCXpresso version 6 IDE is free tousers of LPC ARM-based microcontrollers.With support for Windows, Mac and Linux

More products in stock, in volume.Search our inventory today.


21

operating systems, it provides for C and C++development projects. Subject to a 256kBdownload limit, the free version of LPCXpressooffers advanced hardware debug capabilities,including trace. It is simple to register andactivate LPCXpresso at www.LPCWare.com. Active users may benefit from the LPCXpressoforum, which now has more than 5,000members, providing design engineers with apeer network for knowledge sharing andproblem solving.

www.futureelectronics.com

LPC1500 board provides platform for experimenting with NXP’slatest ARM Cortex-M3 MCU


Motor-control and digital-power applicationsThe LPCXpresso board with NXP's LPC1549 ARMCortex-M3, see more details on page 2.Orderable Part Number: OM13056

FREEBOARDS

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T E C H N I C A L V I E W

This article, by Peter Bensch, Technical Sales Manager,Future Electronics (Germany), describes an approach to thedesign of the power supply for a modular LED luminaire thatcombines low bill-of-materials cost, low EMI andconsiderable flexibility in production. Using a newlydeveloped microcontroller that has features specially chosenfor their applicability to LED power systems, this approachenables luminaire manufacturers to produce a broad range ofproducts more cheaply than before, and thus profitablyappeal to a more diverse range of customer requirements.

The inflexibility of standard power suppliesThe electronics industry provides lighting equipment manufacturers witha broad choice of off-the-shelf, certified power-supply modules speciallydesigned to drive LEDs. Integrating such a module is a quick andstraightforward task. This is perfect for manufacturers that only want toproduce LED luminaires with a known, fixed light output, since astandard LED power module typically has a fixed constant-current orconstant-voltage output.

The market for lighting equipment, however, is both huge and diverse.Customers call for a dizzying variety of styles and sizes of luminaire withmany different levels of light output. Meeting these diverse needsprofitably is difficult if the manufacturer creates a wholly new powersupply for every new product variant.

A more efficient approach is to create a modular power-systemplatform that can be easily and cheaply modified to supply a wide varietyof end-products.

But now the market’s wide choice of standard, fixed-output powermodules appears to be too inflexible, since different luminaires willrequire different power outputs. The point of a modular design, on theother hand, is that most components, including the power supply,should be common to all product variants.

There is another choice available to the system designer: aconfigurable power-supply module that offers a range of power outputsfrom one unit; the designer selects the required configuration through asimple end-of-line programming procedure. So a single configurable unitcould support multiple variants of a luminaire design. Such programmablemodules are available today from suppliers such as Philips Lighting, withits Xitanium range, and Roal.

A new modular architectureThanks, however, to the introduction of a new type of digital controlleroffering lighting-specific functions, a new modular power architecturecan be implemented profitably by luminaire manufacturers. Since itoperates like a microcontroller, it gives the designer the opportunity toeasily integrate additional features that are valuable to a lightingapplication.

This new architecture uses the controller to switch between parallelstrings of dimmable LEDs, as shown in Figure 1. The controller switchesthe LED strings in such a way as to minimise the input ripple current:this reduces the incidence of EMI while also keeping the Bill-of-Materials(BoM) and certification costs as low as possible.

Different luminaire designs can be made by varying the number andlength of the strings. An external AC-DC power module provides aconstant voltage higher than the forward voltage of the longest LEDstring. Thus an almost infinite variety of luminaire power supplies can berealised with a single PCB design common to all.

READ THIS TO FIND OUT ABOUT

• The advantages to lighting OEMs of using a power-supply platformdesign

• The cost and performance benefits of realising a modular powersupply design with the STLUX385A

• How to avoid the risk of EMI when switching multiple strings of LEDs

Fig. 1: a single controller can reliably control the power supply to multiple LED strings

Anewapproach todesig

F R E E D E V E L O P M E N T K I T S A T W W W . M Y - B O A R D C L U B . C O M22

As well as making system design simpler and accelerating time tomarket, this approach has another benefit: conventional high-intensityLED luminaires typically use a long string of LEDs in a serialconfiguration. The power supplies for such serial strings have very highvoltages that require insulation for safety reasons. By contrast, multipleshorter strings of LEDs in parallel operate at a safe low voltage, and sorequire no protection against electric shock.

Preventing excessive EMIThe main issue facing the designer when implementing this architecture isto avoid the generation of harmful levels of EMI and ripple current arisingfrom the many switching operations to which the board is subjected. It isnormal to synchronise PWM drivers running at the same switchingfrequency to avoid interference and the potential for audible noise. Initself, this is quite easy to do. But it still leaves sensitive components onthe board open to the risk of damage by high peak ripple currents.

Ripple current is generated at the edges of power switching cycles. Ina system with several synchronised driver circuits, the ripple currentsgenerated by the multiple simultaneous edges are combined, creating alarge peak ripple current.

To avoid damage to other circuit components, the ripple current peakneeds to be kept to a low value. A way to do this is to space out thefalling edges, so that they do not occur simultaneously; the averageripple current stays the same, but the peak ripple current is lower. Thisinterleaving can be achieved by phase-shifting the switching of the drivers.

In the past, the complexity of such a design might have been thoughtundesirable in an LED power supply. But the semiconductor industry hasnow stepped in to make the implementation of this kind of design mucheasier than before. The new MASTERLUX™ family of digital controllersfrom STMicroelectronics has been created to provide the functionsrequired by today’s LED power designs, including phase-shifting.

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ning flexible LEDdriversIn the STLUX385A, ST’s first MASTERLUX device, phase-shifting ofswitching operations is realised by an innovative digital technology calledState Machine Event Driven (SMED). The SMED is a 96MHz statemachine, implemented in hardware and triggered by internal or externalevents. It replaces and extends the functions that might otherwise beprovided by analogue blocks in a traditional microcontroller.

Used as an LED driver controller, the SMED can close the regulationloop and automatically switch off the driver when it detects anovercurrent or a short circuit. Since SMED blocks are entirelyimplemented in hardware, they guarantee an event reaction time shorterthan that provided by any standard interrupt-driven microcontrollerprocessor core. This means that the required duty cycle for each LEDchannel will be executed on schedule, allowing for accurate and reliableregulation of light intensity.

The STLUX385A contains six SMEDs; each can be used to controlone PWM LED driver. The driver itself is implemented outside thecontroller, for instance in a discrete buck regulator. STMicroelectronicsprovides a development tool for the SMED peripherals. It includes apowerful graphical SMED configurator which directly generates C code.The designer inputs the number of LEDs per channel, LED specificationsand required average current through the LEDs, and the tool computesthe required duty cycles and PWM configurations. The STLUX385A canalso provide automatic compensation for the depreciation of the LEDs’light output over time.

An example designA useful way to see how the STLUX385A can be used in a multi-channelLED design is to study an example developed by STMicroelectronics. Itsevaluation module STEVAL385LED4CH (described in detail in applicationnote AN4291 at www.st.com) consists of four phase-shifted LEDchannels operating at an efficiency of up to 98%, all controlled by asingle STLUX385A.

The evaluation board can be configured in a variety of ways, and thusprovides a useful starting point for many luminaire manufacturers’platform power designs. It will operate from any DC input between 12Vand 48V. The power supply can drive and dim from three to ten LEDsper channel, with a maximum total power of 200W.

ST has chosen not to use the common buck-converter topology, asshown in Figure 2. Instead, this system uses a reversed buck topologyto control a low-cost N-type MOSFET without boost capacitors. Thisreduces BoM cost, and also allows for the easy ground-referencedmeasurement of the switch current.

In the schematic for LED channel 0, as shown in Figure 3, L3, D4 andC11 form the reversed buck circuitry. D6 is a Schottky diode protectingthe circuitry in case the LED string opens. The gate driver, U2, is used todrive the LED forward voltages: these are higher than the direct-drivecapability of the STLUX385A, which is powered from a 3.3V supply rail,can support. The R28 and R29 shunt resistors gauge the switch current,supplemented by a spike filter formed by R23/C14. Q4 together with U5capture the LED voltage, to support the protection features of theSTLUX385A.

By configuring the PWM signal at the controller appropriately, each ofthe four LED channels’ power circuits can be phase-shifted to avoidgenerating high peak ripple currents, as shown in Figure 4.

Fig. 4: the SMED peripherals in the STLUX385A can be easily configured to phase-shift up to six LEDchannels’ switching operations

Fig. 3: the PWM signal from the STLUX385A controls a reversed buck converter at each LED channel

Fig. 2: common buck converter circuit (left side) and the reversed buck converter topology (right side) asused in the STLUX385A demonstration system

Additional useful featuresThe PWM control function described above is the core capabilityenabling the design of a modular power supply for LED luminaires. But afurther advantage of using an integrated controller is that it providesadditional features that are useful in an LED lighting system. These include:• Built-in support for control interfaces such as DALI, DMX-512, KNX (in

tandem with an external KNX transceiver such as the NCN5120 fromON Semiconductor) and 1-10V control

• Flexible ramp-up/ramp-down routines• Automatic adjustment in response to ambient light, when combined

with a digital ambient light sensor such as the APDS-9301 fromAvago Technologies, the BH1721FVC from ROHM or the TSL4531from ams.

• Error log

ConclusionThe STLUX385A provides all necessary control functionality to create ahighly efficient, very flexible and powerful LED driver for luminaires. Theproposed system solution keeps EMI within safe limits by using aninterleaved switching scheme, and fulfils safety requirements by using asafe low voltage. At the same time, this solution is cheap to implement,because the switching scheme enables a single low-cost controller tocontrol as many as six independent strings of LEDs.

application spotlight on analogue and sensing · application spotlight on analogue and sensing. ......

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