Radoslav Danilak Co-founder & CEO of Skyera

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Overview of the

Wandboard featuring the Freescale i-MX6 processor

The Wandboard is a non-for-profit modular development board that is created by Wandboard.org, whose goal was to create a low-cost, flexible, and accessible development board. The development board features the Freescale i.MX6 family of processors, and it comes in solo, dual, and quad core versions. As a modular board it includes both a processor board and an interface board, and comes with a custom enclosure for protecting the unit and for taking it outside the lab.

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4Radoslav DanilakCO-FOUNDER & CEO OF SKYERA

How this new enterprise storage company is making waves with its solid-state array.

10Featured ProductsThis week’s latest products from EEWeb.

14SkyHawk Storage SystemSkyera’s all-Flash array overcomes common

endurance limitations, making it 10x more reliable than eMLC Flash.

20Product Overview: Wandboard

A new take on development kits.

26How to GaNA look at driver and layout considerations to improve the performance achieveable

with GaN FETs.

35RTZReturn to Zero Comic

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32The Robots of NASAThese complex robots pose unique design challenges in order to navigate a planet’s

rugged terrain.

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Skyera is a rising provider of enterprise storage systems. Founded in 2012, Skyera has been making waves in the industry with their extraordinarily high performance storage system, the skyHawk. This groundbreaking storage platform combines affordability and unparalleled speeds and capacity.

The company’s co-founder and CEO, Radoslav Danilak, has been in the solid-state storage industry his entire career. From the memory division of Toshiba to creating the world’s best Flash controller at SandForce, Danilak assembled a qualified team from his past experiences to start a company aimed at transforming the industry. We spoke with Danilak about the company’s unique approach to innovation and how they integrated off-the-shelf components to create a storage system that far surpasses any other system on the market today.

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INTERVIEW

Skyera is a rising provider of enterprise storage systems. Founded in 2012, Skyera has been making waves in the industry with their extraordinarily high performance storage system, the skyHawk. This groundbreaking storage platform combines affordability and unparalleled speeds and capacity.

The company’s co-founder and CEO, Radoslav Danilak, has been in the solid-state storage industry his entire career. From the memory division of Toshiba to creating the world’s best Flash controller at SandForce, Danilak assembled a qualified team from his past experiences to start a company aimed at transforming the industry. We spoke with Danilak about the company’s unique approach to innovation and how they integrated off-the-shelf components to create a storage system that far surpasses any other system on the market today.

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How does Skyera differ from your previous Flash ventures?

During my previous tenure, the NAND Flash vendors were always viewed as potential competitors. Instead of selling us NAND for 40% margins, they wanted to sell it for 50%, which completely makes sense. At Skyera, what is fundamentally different is that these vendors know that we are so far separated from components that cooperation is not a problem. In fact, most of the largest manufacturers of the NAND Flash commodity components are investors in our company.

Flash is the new storage media. If you want to use this media, you have to have a semiconductor background and you have to understand the media. So we got the father of MLC NAND Flash, Prof. Ken Takiuchi working with us, who introduced MLC NAND Flash when he was a designer at Toshiba. On top of that, we have Frankie Roohparvar, who has more than 450 granted patents in NAND Flash design over the last 19 years. He was the guy behind Micron and Intel’s NAND Flash technology. We also have the best core group of engineers from SandForce working with talented teams from the storage hardware and software space.

I founded Skyera in 2012 and today a majority of the company has an engineering background. Skyera’s core competency is engineering and the mixture is of semiconductor guys, hardware designers, system designers, and software engineers. The company is not funded by venture capital, which is very unusual. At the

beginning it was self-funded, but then Western Digital, the world largest hard drive vendor, basically saw how these two technologies could amplify each other and provided initial funding for us. In January, we announced a $51 million institutional funding round led by Dell Ventures and several NAND Flash vendors.

Do you see your company more as a product developer than a technology developer?

If you are just a technology developer that gets say 10 cents per gigabyte, it’s very difficult to build a good licensing business model. We are definitely focusing on complete products. We will sometimes partner with other companies, but we are not a licensing house. We produce enterprise storage systems, which we are selling directly to end user customers, channel and OEMs. Our philosophy is a little bit different. We believe that our core structure is so good that both Skyera and OEMs can comfortably make a living. We have a steadily growing OEM business. With these other large companies, if you try to argue that EMC or NetApp will disappear in two years, it’s just nonsense. Instead of going to futile “war” with other competitors, we will appreciate them as customers, which is way more productive and it helps everybody. Philosophically, our company is focused on what the customer wants. It cannot be OEM only since we would be one step removed and not directly in touch with customers to learn what they want and that is key for our success. At the same time, we are focusing on partnerships rather than creating competitors.

“ At Skyera, what is fundamentally different is that these vendors know that we are so far separated from components that cooperation is not a problem. In fact, most of the largest manufacturers of the NAND Flash commodity components are investors in our company.”

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INTERVIEWIs your solid-state memory device using SSDs from a manufacturer like Micron, Intel or Samsung, or are you developing a custom-designed system?

Excellent question. If you look at SSDs, most of them are commodity or consumer grade and others are built for existing storage systems so they can plug them into the system and sell them. What we realized in the beginning was that plugging solid-state into existing ecosystems using SSD was not the way to go. We realized that SSD-based arrays, which are different than solid-state arrays, have no future in the market. We therefore decided not to build pure imitations of these SSD-based systems. If you are building storage arrays from SSDs, they are way more expensive because of margin stacking where SSD vendors buy chips and software to support their NAND Flash with profit margins from each component raising the cost of the SSD.

The economical advantage is that we removed the margin stacking by buying all the NAND Flash components and developing an onboard Flash controller and other intellectual property in-house. This allows us to achieve much better efficiency and lower costs than SSD-based systems. Historically, if you look at when the new generation Flash showed up, typically SSDs use Flash with a 12-month delay. If you are buying SSDs, you will be stuck with older generations of Flash because of this delay. Having our own controller puts us ahead of the SSD-based storage array vendors and able to take advantage of the most advanced Flash.

How does your product compare to those efforts other companies are making in terms of data rates and speeds?

Because the volume of solid-state drives was just 0.3% of the enterprise storage market, nobody could afford to build a system around the Flash. What do you do? You design a system around SSDs—things that use the

“A solid-state array, such as Skyera’s skyHawk, adds a comprehensive set of enterprise storage

services, including data deduplication and compression, thin provisioning, Flash-optimized

RAID and storage QoS.”

skyHawk Stack

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same protocol as hard drives—and plug them into existing systems because nobody had economic incentive to build around it. Once the volume picked up, people started saying, “Twenty years of hard drive industry legacy protocols, adding density, adding latency—we are not extracting the full benefits from solid-state media.” They started removing the protocols, which is why the PCIe solution they have is in place. If you look at existing disk storage systems, out of a $37 billion industry, internal storage is still only $8 to $9 billion. The PCIe solution is still internal storage and does nothing to address the needs of the majority of the market. The third level of evolution is shared storage. The missing final stage of the evolution we are bringing is moving from solid-state appliances to solid-state arrays. That’s an important distinction that’s often overlooked. A solid-state appliance can connect to servers, but it’s not developed for primary storage. A solid-state array, such as Skyera’s skyHawk, adds a comprehensive set of enterprise storage services, including data deduplication and compression, thin provisioning, Flash-optimized RAID and storage QoS. So the big difference is that PCIe Flash is targeted at a small niche of the storage market, while Skyera is designing for mainstream enterprise storage.

I think lately, the main message our competitors try and spread is that because we are using this most advanced Flash with fewer programming cycles than what they claim to be using, they’re trying to tell enterprise customers, “Are you sure you want that latest generation Flash? It’s really not as reliable as what we’re trying to sell you. And by the way, that’s why ours costs more.” If you build the right system, then that variable is completely removed from the equation and I think that is an important point.

Not surprisingly, those competitors aren’t telling you the whole story. Skyera was founded to create a transformational solid-state storage system: an enterprise, pure solid-state array at the unprecedented cost of $3 per gigabyte. Reaching that cost target with older generations of SLC or eMLC Flash wasn’t

possible. This necessitated the use of the Most Advanced NAND Flash—or MAN Flash as we like to call it. The challenge then was how to use MAN Flash and achieve enterprise-class durability and reliability. As I mentioned previously, Skyera has the best Flash engineers and designers in the industry and we developed a fully integrated hardware and software stack that provides 100x life amplification with this MAN Flash. This is achieved by minimizing writes to the Flash, a new ultra-efficient RAID technology designed specifically for Flash that eliminates much of the legacy disk-based RAID overhead, new DSP and ECC technologies, and adaptive reads and writes based on the condition of the Flash media. The combination of these life amplification technologies produces a 5-year or greater life expectancy for Flash media in skyHawk, far beyond the requirements for enterprise environments. ■

“ Skyera has the best Flash engineers and designers in the industry and we developed a fully integrated hardware and software stack that provides 100x life amplification with this MAN Flash.”

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Audio Amp for SmartphonesAs smartphone connectivity becomes increasingly central to automotive infotain-ment applications, the industry has to ensure that audio quality is not compromised by smartphone signal interference. Designed specifically for automotive applications, NXP’s Class-AB audio amplifiers provide increased GSM robustness to mitigate the influence of smartphones on loud speakers, responding to OEMs’ demand for a cost-effective solution that improves sound quality...Read More

Low-Power RAM for Imaging ApplicationsThe new Renesas RZ/A1 group features a high-performance ARM Cortex-A9 core op-erating at 400MHz and a large 10MB on-chip RAM that can buffer the data needed to drive displays up to WXGA (1280×768) without the need for external DRAM memory. By eliminating the external DRAM memory, system BOM cost and power are significantly reduced. The lack of external DRAM reduces the number of switching signals and miti-gates electromagnetic interference (EMI) concerns. System designs become simpler, enabling customers to bring their products to market quicker...Read More

Halogen Free Driver AmplifierAvago Technologies’s MGA-30489 is a 0.25W highly dynamic range Driver Amplifier MMIC. It is housed in a SOT-89 standard plastic package. MGA-30489 features ex-cellent input and output return loss and highly linear performance. The device can be easily matched to obtain optimum power and linearity. MGA-30489 is especially ideal for 50Ω wireless infrastructure application such as Cellular/PCS/WCDMA/WLL and new generation wireless technologies systems in the 250MHz to 3GHz frequency range applications...Read More

1A Simple Switcher Nano ModuleThe LMZ10501 Simple Switcher nano module is an easy-to-use step-down DC-DC solution capable of driving up to 1A load in space-constrained applications. Only an input capacitor, an output capacitor, a small VCON filter capacitor and two resistors are required for basic operation of this module. The nano module comes in 8-pin POS footprint package with an integrated inductor. Internal current limit based soft start function, current overload protection and thermal shutdown are also provided. The device also features an integrated inductor...Read More

2.2 MHz PMIC for Automotive ConvertersThe 1.2A output high-efficiency, step-down DC-DC converter (OUT1) operates from a voltage up to 28V continuous and is protected from load-dump transients up to 45V. The 600mA output high-efficiency step-down DC-DC converter (OUT2) runs from a voltage up to 5.5V. The two 300mA LDO linear regulators offer low dropout of only 130mV (typ). The power-good active-low RESET output provides voltage monitoring for OUT1 and OUT2. OUT1 and OUT2 use fast 2.2MHz PWM switching and small exter-nal components...Read More

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FEATURED PRODUCTS

High-Efficiency Solar ModuleOxford University’s Eco-Vehicle, named “Peggie”, features a reconfigurable PV array, using the IXYS SolarMD modules SLMD121H09L that manoeuvres the maximum power point of the solar panel to coincide with the battery terminal voltage. IXOLAR SolarMD is an IXYS product line of Solar Module made of mono-crystalline, high efficiency solar cells. The IXOLAR SolarMD is an ideal for charging various battery powered and hand-held consumer products such as mobile phones, cameras, PDAs, MP3-Players and toys...Read More

Sprite-based Graphics ControllerMB88F332 ‘Indigo’ is Fujitsu’s first sprite-based Graphics Controller. MB88F332 is a 180nm embedded flash CMOS device, which targets automotive applica-tion fields, especially state-of-the-art systems, CID (Central Information Display) and RSE (Rear Seat entertainment) systems. The need for expensive framebuffer VRAM memory is eliminated as graphics processing is done entirely on a line-based scheme. A suite of 5V MCU peripherals such as SMC (Stepper Motor Con-trollers), PWMs (Pulse Width Modulators) and ADCs (Analog-Digital Converters) is integrated to enable the realization of competitive systems...Read More

Quad-Frequency Programmable XOThe IDT 8N3Q001 is a Quad-Frequency Program-mable Clock Oscillator with very flexible frequen-cy programming capabilities. The device uses IDT’s fourth generation FemtoClock NG technol-ogy for an optimum of high clock frequency and low phase noise performance. The device ac-cepts 2.5V or 3.3V supply and is packaged in a small, lead-free (RoHS 6) 10-lead Ceramic 5mm x 7mm x 1.55mm package...Read More

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HD/SD DVR Video Port ExpanderTW2828 is a display and recording MUX chip with HD SPOT capability designed to work with the popular H.264 CODEC on the market today. The device provides a clean and cost effective MUX solution to the multi-channel PC HD DVR marketplace. The TW2828 Digital Input Ports support input resizing, cutting and cropping and even Channel cascading. It’s Display Controller is even capable of Motion Box on all live channels On the embedded DVR market, using TW2828 in conjunction with a host SOC can deliver the most cost effective solution on the market...Read More

Rapid-Charging Interface ICPower Integrations introduced Chy100, the first AC-DC wall-charger interface IC that enables designers of mobile devices to implement the Quick Charge 2.0 protocol from Qualcomm (Nasdaq:QCOM). Launched earlier this year, Quick Charge 2.0 enables users to charge mobile devices up to 75% faster than when using conven-tional technology. Used in combination with Power Integrations’ AC-DC switcher ICs, the CHY100 incorporates all the necessary elements required to add Quick Charge 2.0 functionality to AC-DC wall chargers...Read More

USB3 Controller Hubs with Flash MemoryMicrochip Technology Inc. announced its third-generation USB3 Controller Hubs (UCH3s)—the four-member USB553XB-5000 family which is SuperSpeed Logo Certified by the USB Implementers Forum and is the world’s first to integrate OTP Flash con-figuration memory. This UCH3 family is also the industry’s most flexible, as it includes a seven-port hybrid version with a certified four-port USB3 hub and three additional USB2 lanes. The designers of computing and peripheral platforms are rapidly adopt-ing the USB3 standard for its increased bandwidth of 5 Gbps and higher-power charging ports...Read More

Differential Pressure SensorMouser Electronics, Inc. is now offering Omron Electronics D6F-PH Series Differential Pressure Sensor, a new type of MEMS flow sensor with I2C digital output. Based on Omron’s proprietary MEMS mass flow technology, a redesigned internal flow path produces a high velocity/high impedance sensor with differential pressure output. Resistant to bypass tube length variation, the D6F-PH sensor is ideal for field-installed HVAC damper controls where tube lengths are often inconsistent...Read More

Compact 3.6 x 10 mm Pigtal FuseIntroducing the 874 Series axial lead & cartridge fuses from Littlefuse. This device boosts an overall dimension of 3.6 X 10 mm. The more compact footprint was made possible by doing away with conventional over-capping (single pigtail). This series also offer higher I2T values than similar over-capped offerings in the market. This space saving fuse is ideally suited for lighting, power supply, and adapter applica-tions. They are suitable for end applications that are more susceptible to higher frequencies of surges/transients...Read More

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FEATURED PRODUCTS

Programmable Stepper Motor DriverThe A4979 is a flexible microstepping motor driver with built-in translator for easy op-eration. It is a single-chip solution, designed to operate bipolar stepper motors in full-, half-, quarter- and sixteenth-step modes, at up to 50 V and 1.5 A. The A4979 can be controlled by simple Step and Direction inputs, or through the SPI-compatible serial interface that also can be used to program many of the integrated features and to read diagnostic information...Read More

Automotive Qualified Angle SensorAK740X product family comprises the 12bit angle sensor AK7401 with serial / PWM interface as well as the high speed 12bit angle sensor AK7405 with serial / ABZ interface. The AK7401 is an automotive qualified 12bits angle sensor which detects the angular position of a magnetic field parallel to the IC surface. The contactless angle sensor can be made by the simple construction containing small magnet and this sensor. AK7401 is suitable for the rotational position sensing application, for example steering angle measurement, valve position sensin..Read More

3-Channel CMOS LDOsROHM’s BU665xNUX series of 3ch CMOS LDO regulators provide 200mA output in a combination of voltages. Additional features include excellent noise and load response characteristics with a circuit current of only 120µA in a compact surface mount package (VSON008X2030: 2.0×3.0×0.6mm). Ideal for power supplies in a variety of applications, including logic ICs, RF circuits, and camera modules. The devices also have an output voltage accuracy of ±1%...Read More

Sensorless BLDC Motor ControllerThe MLX81200 is a highly integrated 3 phase motor controller for 12V automotive applications. It includes a 16-Bit Flash Microcontroller with a high voltage analog periphery for BLDC motor driving in a very small package. Therefore, the MLX81200 enables the industry’s smallest control electronics opening a new dimension in system inte-gration. Its TruSense technology enables sensorless motor driving for a wide range of applications requesting an “on demand” control.

Features:• Fast start-up, accelerate and run under unknown load conditions• Low noise operation• Block, trapezoidal and sinusoidal motor currents

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TECH ARTICLE

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Utilizing 19/20nm Flash Devices

Skyera has implemented the most advanced 19/20nm MLC in the skyHawk solid-state storage system. Because the dual flash devices in the flash module are 19 and 20 nanometers—typical consumer-grade device sizes—the overall cost of the system is reduced without sacrificing any of the endurance or performance. The skyHawk is one of the only all-flash arrays to break the price barrier for mainstream enterprise adoption, bringing industrial-grade quality to the mainstream consumer market. While counterpart options like eMLC and SLC offer a significantly higher amount of write cycles than traditional MLC, that does not mean there is a lower probability of data loss than 19/20 nm MLC. However, this notion of higher endurance only applies to specific systems that these all-flash vendors create. Skyera has raised the bar considerably for consumer-grade flash vendors in that they achieve enterprise-level reliability in their system.

100x Life Amplification

In order to achieve enterprise-level reliability with the latest generation of flash, a system needs to have 100x Life Amplification™. With the skyHawk system, Skyera achieved this through a system-wide approach. For Skyera’s design team, this entailed developing and

The skyHawk is one of the only all-flash arrays to break the price barrier for mainstream enterprise adoption, bringing industrial-grade quality to the mainstream consumer market.

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TECH ARTICLE

consolidating all of the components in this technology stack. The stack includes flash and RAID controllers, storage nodes and a network interface, eliminating the need for external devices like SSDs. Skyera’s RAID-SE ensures more reliable storage in the system. If flash storage in the module is lost, Skyera’s RAID functionality allows the user to recover the data—effectively acting as a data protection capability. There is also significant optimization made to the amount of writes on the flash itself. With the introduction of “soft writes” that reduce flash substrate degradation, the skyHawk system has an extended life of up to five years of enterprise usage—the market-leading standard.

Optimized Networking Channels

Another optimized part of the skyHawk system is the iSCSI channel between the network switch and storage array. With 40 1-Gigabit and 310-Gigabit Ethernet ports, the

skyHawk can connect to traditional Ethernet switches, eliminating the need for external components. This also eliminates the potential bottlenecking of data access that can occur when a system’s iSCSI channels are oversaturated. Because of this, the skyHawk can connect to a server without an Ethernet switch. “This is a huge benefit,” states Radoslav Danilak, CEO of Skyera, “It allows [the user] to double the performance of the storage without having any additional expense. Our customers like that.”

With optimized hardware in both the front and back-end, Skyera has developed an entirely vertically integrated, all-flash solution capable of competing with industrial eMLC and SLC—all within the mainstream market. ■

With 40 1-Gigabit and 310-Gigabit Ethernet ports, the skyHawk can

connect to traditional Ethernet switches, eliminating the need for

external components.

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Overview of the

Wandboard featuring the Freescale i-MX6 processor

The Wandboard is a non-for-profit modular development board that is created by Wandboard.org, whose goal was to create a low-cost, flexible, and accessible development board. The development board features the Freescale i.MX6 family of processors, and it comes in solo, dual, and quad core versions. As a modular board it includes both a processor board and an interface board, and comes with a custom enclosure for protecting the unit and for taking it outside the lab.

not

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PRODUCT OVERVIEW

Overview of the

Wandboard featuring the Freescale i-MX6 processor

The Wandboard is a non-for-profit modular development board that is created by Wandboard.org, whose goal was to create a low-cost, flexible, and accessible development board. The development board features the Freescale i.MX6 family of processors, and it comes in solo, dual, and quad core versions. As a modular board it includes both a processor board and an interface board, and comes with a custom enclosure for protecting the unit and for taking it outside the lab.

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Included HardwareThe Freescale i.MX6 series processors are pin-for-pin and software compatible, which means that if you need to go from the solo to the dual processor (or the dual to the quad processor) you won’t have to recode everything, or re-layout your board. You will probably have to do some coding to take advantage of the additional costs, but other than that, you’ll be ready to go.

Besides the Freescale i.MX6 series processors, the Wandboard also comes with 4 DDR3DRM ICs, a Micro SD Connector, WiFi and Bluetooth integrated modules, and a 315 Pin Edge Connector (in compliance with the EDM standard). It also includes a

reset button and expansion headers, which have your GPIOs, LBDS signals, I2C Busses, SPI Busses, and a connector for your stereoscopic camera

interface.

On the front side of the board you can find your 5V in, RJ45, HDMI, Digital Audio, Microphone In, Line In, Line

Out, Serial, SATA, High Speed USB 2.0, a MicroSD slot for storage and applications, and USB

On-the-Go connector ICs. Included in the development board you will also find

your ADM 3202 2-Channel, low power high speed

RS232 interface, the Freescale SGTL 5000 Ultra Low Audio CODEC, the AME 8816 LDO

(which converts your 5V In to the 3.3V supply you

need for the board) and the TPS 2061, a power switch for the

On-the-Go USB. the AC+ and AC- test points, depending on what type of

voltage you have.

SetupTo set up your board, begin by downloading the Ubuntu 11.10 Version from the website and burn it onto a Micro SD card on the back. You should then be able to see Ubuntu Version 11.10 running on the Wandboard. At that point, you will want to make sure the HDMI output is plugged into the HDMI input on the laptop. Note that besides the Ubuntu Version 11.10, you can also download Android Jelly Bean.

Make sure your WiFi antenna is hooked up. On mouser.com you can get the WiFi antenna kit that includes the appropriate cable (as well as a custom enclosure) if you do a keyword search for “Wandboard” or pull up the Wandboard product page, which should be listed in accessories.

ConclusionThe Wandboard is a new take on development kits. By making the processor board and the essential functions of the unit more modular and the interface board a second board, the Wandboard allows you to customize your interface to your needs. It has basically everything you would need to design a system integrated into a single chip.

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Typical Uses and SetupA typical use for the Wandboard is something like a streaming music or media player. For these, or a similar uses, you’d want to put the board in the custom enclosure, hook it up to your TV via HDMI, and start streaming media from your USB drive or across your network. The advantage of this is, wherever you store your media, you should be able to access it.

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PRODUCT OVERVIEW

Included HardwareThe Freescale i.MX6 series processors are pin-for-pin and software compatible, which means that if you need to go from the solo to the dual processor (or the dual to the quad processor) you won’t have to recode everything, or re-layout your board. You will probably have to do some coding to take advantage of the additional costs, but other than that, you’ll be ready to go.

Besides the Freescale i.MX6 series processors, the Wandboard also comes with 4 DDR3DRM ICs, a Micro SD Connector, WiFi and Bluetooth integrated modules, and a 315 Pin Edge Connector (in compliance with the EDM standard). It also includes a

reset button and expansion headers, which have your GPIOs, LBDS signals, I2C Busses, SPI Busses, and a connector for your stereoscopic camera

interface.

On the front side of the board you can find your 5V in, RJ45, HDMI, Digital Audio, Microphone In, Line In, Line

Out, Serial, SATA, High Speed USB 2.0, a MicroSD slot for storage and applications, and USB

On-the-Go connector ICs. Included in the development board you will also find

your ADM 3202 2-Channel, low power high speed

RS232 interface, the Freescale SGTL 5000 Ultra Low Audio CODEC, the AME 8816 LDO

(which converts your 5V In to the 3.3V supply you

need for the board) and the TPS 2061, a power switch for the

On-the-Go USB. the AC+ and AC- test points, depending on what type of

voltage you have.

SetupTo set up your board, begin by downloading the Ubuntu 11.10 Version from the website and burn it onto a Micro SD card on the back. You should then be able to see Ubuntu Version 11.10 running on the Wandboard. At that point, you will want to make sure the HDMI output is plugged into the HDMI input on the laptop. Note that besides the Ubuntu Version 11.10, you can also download Android Jelly Bean.

Make sure your WiFi antenna is hooked up. On mouser.com you can get the WiFi antenna kit that includes the appropriate cable (as well as a custom enclosure) if you do a keyword search for “Wandboard” or pull up the Wandboard product page, which should be listed in accessories.

ConclusionThe Wandboard is a new take on development kits. By making the processor board and the essential functions of the unit more modular and the interface board a second board, the Wandboard allows you to customize your interface to your needs. It has basically everything you would need to design a system integrated into a single chip.

Watch Video

Typical Uses and SetupA typical use for the Wandboard is something like a streaming music or media player. For these, or a similar uses, you’d want to put the board in the custom enclosure, hook it up to your TV via HDMI, and start streaming media from your USB drive or across your network. The advantage of this is, wherever you store your media, you should be able to access it.

For these, or for

Power Factor Correction ControllersISL6730A, ISL6730B, ISL6730C, ISL6730DThe ISL6730A, ISL6730B, ISL6730C, ISL6730D are active power factor correction (PFC) controller ICs that use a boost topology. (ISL6730B, ISL6730C, ISL6730D are Coming Soon.) The controllers are suitable for AC/DC power systems, up to 2kW and over the universal line input.

The ISL6730A, ISL6730B, ISL6730C, ISL6730D are operated in continuous current mode. Accurate input current shaping is achieved with a current error amplifier. A patent pending breakthrough negative capacitance technology minimizes zero crossing distortion and reduces the magnetic components size. The small external components result in a low cost design without sacrificing performance.

The internally clamped 12.5V gate driver delivers 1.5A peak current to the external power MOSFET. The ISL6730A, ISL6730B, ISL6730C, ISL6730D provide a highly reliable system that is fully protected. Protection features include cycle-by-cycle overcurrent, over power limit, over-temperature, input brownout, output overvoltage and undervoltage protection.

The ISL6730A, ISL6730B provide excellent power efficiency and transitions into a power saving skip mode during light load conditions, thus improving efficiency automatically. The ISL6730A, ISL6730B, ISL6730C, ISL6730D can be shut down by pulling the FB pin below 0.5V or grounding the BO pin. The ISL6730C, ISL6730D have no skip mode.

Two switching frequency options are provided. The ISL6730B, ISL6730D switch at 62kHz, and the ISL6730A, ISL6730C switch at 124kHz.

Features• Reduce component size requirements

- Enables smaller, thinner AC/DC adapters- Choke and cap size can be reduced by 66%- Lower cost of materials

• Excellent power factor over line and load regulation- Internal current compensation- CCM Mode with Patent pending IP for smaller EMI filter

• Better light load efficiency- Automatic pulse skipping- Programmable or automatic shutdown

• High reliable design- Cycle-by-cycle current limit- Input average power limit- OVP and OTP protection- Input brownout protection

• Small 10 Ld MSOP package

Applications• Desktop computer AC/DC adaptor

• Laptop computer AC/DC adaptor

• TV AC/DC power supply

• AC/DC brick converters

FIGURE 1. TYPICAL APPLICATION FIGURE 2. PFC EFFICIENCY

+

ISL6730

VCCISEN

ICOMP

VIN

GATEGND

FB

BO VREG

COMP

VLINE VOUT

VI

OUTPUT POWER (W)

EFFI

CIE

NC

Y (%

)

ISL6730C

ISL6730A, SKIP

100

95

60

65

70

90

85

80

75

0 20 40 60 80 100

TABLE 1. KEY DIFFERENCES IN FAMILY OF ISL6730

VERSION ISL6730A ISL6730B ISL6730C ISL6730D

Switching Frequency 124kHz 62kHz 124kHz 62kHz

Skip Mode Yes-Fixed Yes-Fixed No No

February 26, 2013FN8258.0

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2013All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

Get the Datasheet and Order Samples

http://www.intersil.com

Technology You Can Trust

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For more details on this subject, read our white paper at: www.avagoresponsecenter.com/672

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Alex LidowCEO of Efficient Power Conversion (EPC)

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FEATURED ARTICLE

Alex LidowCEO of Efficient Power Conversion (EPC)

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PULSE

Driver Considerations

eGaN FETs operate similarly to MOSFETs with a few exceptions, the most important being the gate voltage is limited to a maximum of 6 V. To maximize eGaN FET performance it is recommended to drive the devices between 4 to 5 V, as shown in Figure 1. The lower maximum gate voltage makes it advisable to employ gate drive circuitry that can regulate the voltage to ensure safe operation. In collaboration with Texas Instruments, a series of drivers have been developed to bring simplicity and reliability to the challenges of driving eGaN FETS. This family of drivers allows designers to easily adopt the use of eGaN FETs for use in most applications.

To read the previous installment, click below:

The previous columns in this series discussed the benefits of eGaN® FETs and their potential to achieve higher efficiencies and higher switching speeds than possible with silicon MOSFETs. This installment will discuss driver and layout considerations to improve the performance achievable with eGaN FETs.

Figure 1: eGaN FET on resistance vs. gate voltage for various temperatures

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FEATURED ARTICLE

Layout Considerations

Combining great high frequency performance, low on-resistance, and low package parasit-ics, eGaN FETs offer the potential to achieve performance not possible with aging silicon (Si) technology. With higher switching speeds and lower package parasitic inductance the printed circuit board (PCB) layout becomes a limiting fac-tor in converter performance. The inductance of both the common source inductance (LS) and the high frequency power commutation loop (LLOOP), shown in Figure 2a, greatly impact the loss of a converter, and must be minimized in PCB layout. To illustrate the impact of high frequency loop inductance on circuit performance, Figure 2b shows the efficiency obtained from experimental prototypes with loop inductances ranging from 0.4 nH to 2.9 nH. From Figure 2 it can be seen that by increasing PCB layout loop inductance for eGaN FET based designs the efficiency can decrease by almost 5%.

Another impact of the significantly increased switching speeds provided by eGaN FETs is the voltage overshoot the devices experience in circuit even with small values of high frequency loop inductance when compared with slower, higher-parasitic Si MOSFET devices. Decreasing the high frequency loop inductance reduces overshoot, increasing input voltage capability, and reducing EMI. Figure 3 shows the drain to source voltage waveforms of the synchronous rectifier for eGaN FET designs with a high frequency loop inductance of 1.6 nH and 0.4 nH; the voltage overshoot is reduced from 100% of the input voltage to 25%, respectively.

(a) (b)

(a)

(b)

Figure 2: (a) Synchronous buck converter with parasitic inductances (b) Impact of high frequency loop in-ductance on efficiency for designs with similar common source inductance (VIN=12 V, VOUT=1.2 V, Fs=1 MHz, L=150 nH, eGaN FETs: T: EPC2015 SR: EPC2015, MOSFETs: T: BSZ097N04LSG SR: BSZ040N04LSG)

Figure 3: Switching node waveforms of designs with (a) LLOOP≈1.6 nH and (b) LLOOP≈0.4 nH (VIN =12 V, VOUT=1.2 V, IOUT=20 A, Fs=1 MHz, L=150 nH, eGaN FETs: T: EPC2015 SR: EPC2015)

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Optimizing Layout

The most critical parasitic to reduce is the common source inductance, which is the inductance shared by the high frequency power loop and gate driver loop. To minimize the common source inductance added by PCB layout it is recommended to locate the gate driver loop and high frequency power loop where they have very little interaction. An example layout is shown in Figure 4a, where the gate drive loop, shown in red, and the high frequency loop, shown in yellow, interact only directly next to the eGaN FET, minimizing the common source inductance to the ultra-low internal package inductance offered by the eGaN FET package.

(a)

(b)

Figure 4: Conventional PCB designs with eGaN FETs (a) Lat-eral power loop top view (b) Vertical power loop side view

For the high frequency power loop, there are two conventional PCB layout methods being employed in the majority of converter designs, they are the lateral and vertical high frequency power loop designs. For the lateral power loop design, a top view is shown in Figure 4a with the high frequency loop being shown in yellow, the input capacitors and devices are on the same side of the PCB and the power flows laterally on the top layer of the PCB. The components should be kept in close proximity to minimize the size of the high frequency loop. For the vertical power loop design, a side view is shown in Figure 4b, the input capacitors and devices are placed on opposite sides of the PCB, with the capacitors generally being located directly underneath the devices to minimize the physical loop size. This layout is considered a vertical power loop because the power loop is completed by connecting the input capacitors and devices vertically through PCB vias. Both of these designs have pro’s and con’s that are discussed in detail in an EPC optimizing layout white paper.

To improve performance by combining the strengths and limiting the weaknesses of the conventional lateral and vertical designs, EPC developed an improved layout to minimize PCB parasitic inductance. The side view, shown in Figure 5a, illustrates the concept of creating a low profile self-cancelling loop in a multilayer PCB structure. The design utilizes the first inner layer as a power loop return path. This return path is located directly underneath the top layer’s power loop, allowing for the smallest physical loop size combined with magnetic field self-cancellation.

The introduction of high performance

eGaN FETs offers the potential to switch at

higher frequencies and efficiency than possible

with traditional Si MOSFET technology.

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TECH ARTICLE

By utilizing the optimal power loop, high frequency loop inductance values of under 0.4 nH can be achieved, a 40% reduction of the best conventional PCB layout. This translates into improved performance. The efficiency comparison of buck converters using state of the art 40 V Si MOSFETs and 40 V eGaN FETs with the optimal layout is shown in Figure 5b, the eGaN FET based design can improve efficiency over 3% when compared to the Si MOSFET. With the significantly reduced high frequency loop inductance provided by the optimal layout, a 500% increase in switching speed and a 40% reduction in voltage overshoot, as shown in figure 6, can be achieved compared to the 40 V Si MOSFET benchmark.

Summary

The introduction of high performance eGaN FETs offers the potential to switch at higher frequencies and efficiency than possible with traditional Si MOSFET technology. Combined with improved figures of merit and low parasitic packaging, eGaN FETs require a low parasitic PCB layout to fully utilize the device’s capability. At EPC, we have developed an optimal layout optimal further enhancing the benefits of eGaN FET technology, providing additional efficiency gains and higher voltage operation capability.

The EPC9107 demo board, a 28 V input buck converter employing the optimal layout is available from Digi-Key for evaluation. Visit epc-co.com for more information. ■

(a)

(b)

to comment on the article.

» CLICK HERE

Figure 5: (a) Side view of the opti-mal power loop with eGaN FETs (b) Efficiency comparison of the opti-mal eGaN FET and MOSFET designs (VIN=12 V, VOUT=1.2 V, Fs=1 MHz, L=300 nH, eGaN FETS: T: EPC2015 SR: EPC2015, MOSFETs: T: BSZ097N04LSG SR: BSZ040N04LS G)

Figure 6: Switching node waveforms of optimal eGaN FET and MOSFET designs (VIN=12 V, VOUT=1.2 V, IOUT=20 A, Fs=1 MHz, L=300 nH, eGaN FETS: T: EPC2015 SR: EPC2015, MOSFETs: T: BSZ097N-04LSG SR: BSZ040N04LS G)

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SPECIAL FEATURE

Rovers and Swarms

In 2012 a new Mars rover, the Curiosity, suc-cessfully and dramatically landed on the Red planet, joining the ten-year-old rover, Oppor-tunity, which is still trekking across the surface. The Opportunity and Curiosity rovers represent a class of planetary surface robots – robots which travel overland to study the surface of a planet and which are controlled by a group of drivers back on Earth. Although there are special considerations to take into account when designing these types of robots, such as the harsh environment in which they will function, NASA has been fairly successful with the rovers, according to NASA’s Director of the Intelligent Robotics Group Terry Fong, largely due to the use of sensors that enable the robots to sense the environment surrounding them and stay upright.

One of the disadvantages of rovers, com-pared to other designs NASA is pursuing, is that they require drivers back at Houston for navigation. Although the experience of run-ning Opportunity for ten years has allowed drivers to come up with ever more effective ways of navigating the new rover, Curiosity (such as periodically taking pictures to let driv-ers know if whether or not the robot is moving) a new type of robot that works together in a group, the TETwalkers, may be better suited for navigation of a planet’s surface.

By working together in a group or “swarm,” scientists at NASA hope, that TETwalker robots, which look basically like tiny pyramids, will be

able to navigate a landscape by changing their collective shape to flow over a surface. Individual robots move by changing the size of one leg, which causes the robot to topple in a certain direction. As a whole, the individual moving pyramids will form an amoeba-like entity that can easily adjust for obstacles in a landscape, such as a rock.

Though ANTs bring new technology that could be game-changing, rovers may still have a consirable size advantage over TETwalkers. Although they may be better at navigating than a rover, ANTs may be too small to carry equipment of significant size. Because of this, according to Terry Fong, they may be used more in the construction of buildings or structures, rather than in exploring and collecting data.

Another robot intended to easily navigate a martian or lunar surface is the Athlete, a robot that can both walk and roll over a surface. The ability to “walk” allows the Athlete to have greater freedom and mobility than rolling rovers such as Opportunity and Curiosity, and its size will allow it to carry the complex equipment needed to study and explore on another planet.

The ATHLETE Rover climbing a hill (Image courtesy of NASA)

The Opportunity and Curiosity rovers represent a class of planetary surface

robots – robots which travel overland to study the surface of a planet and which

are controlled by a group of drivers back on Earth.

NASA is pursuing several technolo-gies and designs in the field of ro-botics, each with different purposes and challenges. Robots that drive over a planet’s surface, work on the inside of a space station (and with direct human contact), or navi-gate a planet’s complex surface by working as a swarm, all present special advantages...and different design challenges.

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Smart-SPHERES and Robonauts

Besides robots that might be employed to explore and work on a planet’s surface, NASA is also exploring designs for robots that will function inside space stations, such as the free-flying Smart-SPHERES robots and the humanoid Robonauts.

Smart-SPHERES robots are based on the SPHERES robots, which were originally designed to be test platforms used in space to test con-trol algorithms for flying, rendezvous, and docking. An extension of SPHERES using the Android Smart Phone and various sensors, Smart-SPHERES can autonomously sense and navigate an environment. The advantage of Smart-SPHERES is that they can be told to fly from one location to another, but can figure out how to get from the first point to the second point on their own.

The challenges in designing autonomous, free-flying robots, and any robots that will be working alongside humans, include taking into account the safety of both humans and robots, as well as deciding what applications the robots will work on and how. How the robots will work in conjunction with humans, such as whether they will work before, during, or after humans are working, is something that must be considered.

Other robots that will work in the same envi-ronment as humans, but may eventually also work on martian and lunar surfaces, include the Robonauts, NASA’s humanoid robots that are designed to be dextrous, human-like, and to carry out tasks too difficult, tedious, or dan-gerous for humans. One of the advantages of Robonauts is that they can use the same tools as astronauts, which gets rid of the need for new specialized tools. One of the challenges for designing Robonauts is research and work in HRI, or Human Robot Interaction, smoothing the way for humans and robots to effectively communicate, coordinate, cooperate, and collaborate.

Though robots are being created for many different applications and functions, there is a goal that connects all of the disparate designs. While that goal appears to be to create machines that will operate effectively and autonomously with little direction or over-sight, it seems equally important to create responsive machines that work well around and in conjuncture with humans.

_

This article is part of the Littelfuse Speed2De-sign Program. This year, events will be hosted at NASA Ames Research Center, CA and Johnson Space Center, TX.

To learn more about innovations at NASA and how you can win a trip to one of this year’s Speed2Design events at NASA, please visit www.speed2design.com. ■

Johnson Space Center’s Robonaut (Courtesy of NASA)

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