2-phase stepper-motor driver tca 3727 - cogumelo hobby · semiconductor group 1 1998-02-01 2-phase...

2-Phase Stepper-Motor Driver

Overview Bipolar IC

TCA 3727

Features

• 2 x 0.75 amp. / 50 V outputs• Integrated driver, control logic and current control

(chopper)• Fast free-wheeling diodes• Max. supply voltage 52 V• Outputs free of crossover current• Offset-phase turn-ON of output stages• Z-diode for logic supply• Low standby-current drain• Full, half, quarter, mini step

P-DIP-20-6

P-DSO-24-3

Description

TCA 3727 is a bipolar, monolithic IC for driving bipolar stepper motors, DC motors andother inductive loads that operate on constant current. The control logic and poweroutput stages for two bipolar windings are integrated on a single chip which permitsswitched current control of motors with 0.75 A per phase at operating voltages up to50 V.

Type Ordering Code Package

TCA 3727 Q67000-A8302 P-DIP-20-6

TCA 3727 G Q67000-A8335 P-DSO-24-3

Semiconductor Group 1 1998-02-01

TCA 3727

The direction and value of current are programmed for each phase via separate controlinputs. A common oscillator generates the timing for the current control and turn-on withphase offset of the two output stages. The two output stages in a full-bridge configurationhave integrated, fast free-wheeling diodes and are free of crossover current. The logic issupplied either separately with 5 V or taken from the motor supply voltage by way of aseries resistor and an integrated Z-diode. The device can be driven directly by amicroprocessor with the possibility of all modes from full step through half step to ministep.


TCA 3727

Figure 1 Pin Configuration (top view)

TCA 3727 TCA 3727 G

IEP00696

21

Phase 2

Inhibit

GND

GND

Q21Q11

GND

GND

OSC

11

10 11

10

Q22

9 12

8 13

7 14

6 15

5 16

4 17

3 18

2 19

1 20

1 2RR

V S

Q12

VL

Ι

Phase 1

Ι

Ι

20

Ι

Q12 Q22

Q21

GNDGND

OSCPhase 1 Phase 2

11Ι

R1

IEP00898

10Ι

GND

Q11

VS+ +

LV2R

Inhibit

Ι20Ι21

GND

241232223214205196187178169151014111312

GNDGNDGND

GND


TCA 3727

Pin Definitions and Functions

Pin No. Function

1, 2, 19, 20(1, 2, 23, 24) 1)

Digital control inputs IX0, IX1 for the magnitude of the current of the particular phase.

3 Input Phase 1; controls the current through phase winding 1. On H-potential the phase current flows from Q11 to Q12, on L-potential in the reverse direction.

5, 6, 15, 16(5, 6, 7, 8, 17,18, 19, 20) 1)

Ground; all pins are connected internally.

4 Oscillator; works at approx. 25 kHz if this pin is wired to ground across 2.2 nF.

8 (10) 1) Resistor R1 for sensing the current in phase 1.

7, 10 (9, 12) 1) Push-pull outputs Q11, Q12 for phase 1 with integrated free-wheeling diodes.

9 (11) 1) Supply voltage; block to ground, as close as possible to the IC, with a stable electrolytic capacitor of at least 10 µF in parallel with a ceramic capacitor of 220 nF.

12 (14) 1) Logic supply voltage; either supply with 5 V or connect to + VS across a series resistor. A Z-diode of approx. 7 V is integrated. In both cases block to ground directly on the IC with a stable electrolytic capacitor of 10 µF in parallel with a ceramic capacitor of 100 nF.

11, 14 (13, 16) 1)

Push-pull outputs Q22, Q21 for phase 2 with integrated free wheeling diodes.

13 (15) 1) Resistor R2 for sensing the current in phase 2.

IX1 IX0 Phase Current Example of Motor Status

H H 0 No current

H L 1/3 Imax Hold

LH 2/3 Imax Set

LL Imax Accelerate

typical Imax withRsense = 1 Ω : 750 mA


TCA 3727

1) TCA 3727 G only

17 (21) 1) Inhibit input; the IC can be put on standby by low potential on this pin. This reduces the current consumption substantially.

18 (22) 1) Input phase 2; controls the current flow through phase winding 2. OnH-potential the phase current flows from Q21 to Q22, on L potential in the reverse direction.

Pin Definitions and Functions (cont’d)

Pin No. Function


TCA 3727

Figure 2 Block Diagram TCA 3727

IEB00697

12 9

7

10

8

Q11

Q12

R1

4

1

2

3

OSC

FunctionLogic

+ VL SV+

Ι

GND

Phase 1

Phase 1

Phase 1

5, 6, 15, 16

Phase 2

Phase 2

Phase 2

LogicFunction

Inhibit

18

19

20

17

2R

Q22

Q21

13

11

14

Inhibit

10

11Ι

20Ι

21Ι


TCA 3727

Figure 3 Block Diagram TCA 3727 G

IEB00899

D14D13

D12D11

T14

T12

T13

T11

14 11

9

12

10

Q11

Q12

R1

4

1

2

3

Oscillator

FunctionalLogic

+VL SV+

Ι

11

GND

Phase 1

Phase 1

Phase 1

5-8, 17-19

Phase 2

Phase 2

Phase 2

LogicFunctional

Inhibit

22

23

24

21

2R

Q22

Q21

15

13

16T21

T23

T22

T24

D21 D22

D23 D24

Inhibit

10

Ι

Ι20

Ι21


TCA 3727

Absolute Maximum Ratings

TA = – 40 to 125 °CParameter Symbol Limit Values Unit Remarks

min. max.

Supply voltage VS 0 52 V –

Logic supply voltage VL 0 6.5 V Z-diode

Z-current of VL IL – 50 mA –

Output current IQ – 1 1 A –

Ground current IGND – 2 2 A –

Logic inputs VIxx – 6 VL + 0.3 V IXX ; Phase 1, 2; Inhibit

R1 , R2, oscillator input voltage VRX, VOSC

– 0.3 VL + 0.3 V –

Junction temperature TjTj

––

125150

°C°C

–max. 1,000 h

Storage temperature Tstg – 50 125 °C –


TCA 3727

Operating Range

Parameter Symbol Limit Values Unit Remarks

min. max.

Supply voltage VS 5 50 V –

Logic supply voltage VL 4.5 6.5 V without series resistor

Case temperature TC – 40 110 °C measured on pin 5Pdiss = 2 W

Output current IQ – 1000 1000 mA –

Logic inputs VIXX – 5 VL V IXX ; Phase 1, 2;Inhibit

Thermal Resistances

Junction ambientJunction ambient (soldered on a 35 µm thick 20 cm2

PC board copper area)Junction case

Junction ambientJunction ambient(soldered on a 35 µm thick 20 cm2 PC board copper area)Junction case

Rth jaRth ja

Rth jc

Rth jaRth ja

Rth jc

––

–

––

–

5640

18

7550

15

K/WK/W

K/W

K/WK/W

K/W

P-DIP-20-3P-DIP-20-3

measured on pin 5P-DIP-20-3

P-DSO-24-3P-DSO-24-3

measured on pin 5P-DSO-24-3


TCA 3727

CharacteristicsVS = 40 V; VL = 5 V; – 25 °C ≤ Tj ≤ 125 °CParameter Symbol Limit Values Unit Test Condition

min. typ. max.

Current Consumption

from + VSfrom + VS

from + VLfrom + VL

ISIS

ILIL

––

––

0.216

1.718

0.520

325

mAmA

mAmA

Vinh = LVinh = HIQ1/2 = 0, IXX = LVinh = LVinh = HIQ1/2 = 0, IXX = L

Oscillator

Output charging currentCharging thresholdDischarging thresholdFrequency

IOSCVOSCLVOSCHfOSC

–––18

1101.32.325

–––35

µAVVkHz

–––COSC = 2.2 nF

Phase Current Selection (R1; R2)Current Limit Threshold

No currentHoldSetpointAccelerate

Vsense nVsense hVsense sVsense a

–200460740

0250540825

–300620910

mVmVmVmV

IX0 = H; IX1 = HIX0 = L; IX1 = HIX0 = H; IX1 = LIX0 = L; IX1 = L

Logic Inputs(IX1 ; IX0 ; Phase x)

Threshold

L-input currentL-input currentH-input current

VI

IILIILIIH

1.4(H→L)– 10– 100–

–

–––

2.3(L→H)––10

V

µAµAµA

–

VI = 1.4 VVI = 0 VVI = 5 V


TCA 3727

Standby Cutout (inhibit)

Threshold

Threshold

Hysteresis

VInh (L→H)VInh (H→L)VInhhy

2

1.7

0.3

3

2.3

0.7

4

2.9

1.1

V

V

V

–

–

–

Internal Z-Diode

Z-voltage VLZ 6.5 7.4 8.2 V IL = 50 mA

Power Outputs

Diode Transistor Sink Pair(D13, T13; D14, T14; D23, T23; D24, T24)

Saturation voltageSaturation voltageReverse currentForward voltageForward voltage

VsatlVsatlIRlVFlVFl

–––––

0.30.5–0.91

0.613001.31.4

VVµAVV

IQ = – 0.5 AIQ = – 0.75 AVQ = 40 VIQ = 0.5 AIQ = 0.75 A

Diode Transistor Source Pair(D11, T11; D12, T12; D21, T21; D22, T22)

Saturation voltage

Saturation voltage

Saturation voltage

Saturation voltage

Reverse currentForward voltageForward voltageDiode leakage current

VsatuC

VsatuD

VsatuC

VsatuD

IRu

VFuVFuISL

–

–

–

–

––––

0.9

0.3

1.1

0.5

–11.11

1.2

0.7

1.4

1

3001.31.42

V

V

V

V

µAVVmA

IQ = 0.5 A;chargeIQ = 0.5 A;dischargeIQ = 0.75 A;chargeIQ = 0.75 A;dischargeVQ = 0 VIQ = – 0.5 AIQ = – 0.75 AIF = – 0.75 A

Characteristics (cont’d)VS = 40 V; VL = 5 V; – 25 °C ≤ Tj ≤ 125 °CParameter Symbol Limit Values Unit Test Condition

min. typ. max.


TCA 3727

Quiescent Current IS, IL versusSupply Voltage VS

Output Current IQX versusJunction Temperature Tj

Quiescent Current IS, IL versusJunction Temperature Tj

Operating Condition:

VL = 5 VVInh = HCOSC = 2.2 nFRsense = 1 ΩLoad: L = 10 mH

R = 2.4 Ωfphase = 50 Hzmode: fullstep

0 10 20 30 V 500

10

20

30

40

mA

Ι XX = H

= LXXΙ

jT = 25 C

SΙ

LΙ

LΙ

IED01655

VS

Ι S , LΙ

-25 0 25 50 75 100 C 150

jT

QXΙ

IED01657

0

200

800

400

600

mA

-25 0 25 50 75 100 150C

IED01656

XXΙ = H

= LΙ XX

= 40V

LΙ

LΙΙ S

jT

0

10

40

20

ΙΙ S ,

30

L

mA

VS


TCA 3727

Output Saturation Voltages Vsatversus Output Current IQ

Typical Power Dissipation Ptot versusOutput Current IQ (Non Stepping)

Forward Current IF of Free-WheelingDiodes versus Forward Voltages VF

Permissible Power Dissipation Ptotversus Case Temperature TC

00

0.5

0.2

0.4

0.6

1.0 V 1.5

V F

Ι F

0.8

A

T j

1.0

= 25 C

FlV V Fu

IED01167

P-DSO-24

P-DIP-20

Measuredat pin 5.

IED01660

0

6

8

WtotP

12

100-25 0 5025 75 C 175T c

10

4

2

125


TCA 3727

Input Characteristics of Ixx, Phase X, Inhibit

Oscillator Frequency fOSC versusJunction Temperature Tj

Input Current of Inhibit versus JunctionTemperature Tj

V L = 5V

-6 -5 -2 3.9 2 6

IED01661

0.8

0.4

0

0.4

mA

IXXΙ

0.8

VVIXX

0.2

0.6

0.6

0.2

15

20

25

30

kHz

-25 0 25 50 75 100 125 C 150

V SLVOSZC

= 40V= 5V= 2.2nFOSCf

jT

IED01663


TCA 3727

Figure 4 Test Circuit

Figure 5 Application Circuit

IES00706

1

2

3

17

20

19

18

12 9

7

10

14

11

4 13 8GNDOSC

5, 615, 16

R 11 Ω

R 2Ω12.2 nF

Phase 1

Phase 2

Inhibit

VL VS

Q11

Q12

Q21

Q22

TCA 3727

220 nF 100 Fµ220 nF100 Fµ Ι L Ι S

Ι GND

Ι OSC VOSC

Ι Q

Ι Fu

Ι R

Ι Ru

Satl

-

-

VSatu

VFu

VS

-

VΙVΙ

Ι Ι

Ι Ι L

H

L

H

Ι

10

11

Ι

Ι

Ι

21

20

VFl-

SenseV

V

VSense

IES00707

1

2

3

17

20

19

18

12 3

7

10

14

11

4 13 8GNDOSC

5, 615, 16R 1

1 ΩR 2

Ω12.2 nF

MicroController

Ι

11

20

21

Phase 1

Phase 2

Inhibit

VL VS

Q11

Q12

Q21

Q22

TCA 3727

M

220 nF 100 Fµ

+40 V+5 V

220 nF100 Fµ

10

Ι

Ι

Ι


TCA 3727

Figure 6 Full-Step Operation

t

IED01666

Accelerate Mode Normal Mode

acc

set

L

H

L

H

L

H

Ι

Phase 1

i

Q1

i

Ι

Ι 10

11

seti

i acc

i set

i acc

i

Q2Ι

acc

seti

Ι 21

20Ι H

H

L

L

L

HPhase 2

t

t

t

t

t

t

t


TCA 3727

Figure 7 Half-Step Operation

t

t

t

t

t

t

IED01667

t

Accelerate Mode Normal Mode

t

21Ι

20

Phase 2

ΙL

L

H

H

H

L

Q2Ι

-

-

-

i set

acci

i

set

acc

i

acci

Q1Ι

-

Phase 1

seti

seti

L

acci

H

10

Ι11

ΙH

H

L

L


TCA 3727

Figure 8 Quarter-Step Operation


TCA 3727

Figure 9 Mini-Step Operation

H

L

H

L

H

L

i set

i hold

Ι 10

Ι 11

Phase 1

Ι Q1

t

IED01665

acci

seti

i hold

acci

i

acc

set

i

set

hold

acc

hold

i

i

i

i

Ι Q2

L

H

H

L

L

H

Ι

Ι 20

21

Phase 2

t

t

t

t

t

t

t


TCA 3727

Figure 10 Current Control

OscV

0

Ι GND

V Q12V S+

0

S+ V

V+ S

+ V S

t

t

V FUsat 1V

satu DV satu CV

phase x

phase x

Operating conditions:

V

RL

S = 40 V

= 10 mH= 20

IED01177

0

Ω

2.4 V

1.4 V0

t

t

V Q11

V Q22

V Q21

t

t

T

V L = 5 V

Inhibit

xx

VV

V phase x= H= L

= H


TCA 3727

Figure 11 Phase Reversal and Inhibit

Inhibit

OscillatorHigh Imped.

OscillatorHigh Imped.

Phase 1Phase Changeover

HighImpedance

HighImpedance

HighImpe-dance

Slow Current Decay

Fast Current Decay

IED01178

Ι GND

V Osc 2.3 V

1.3 V0

L

LΙ N

0

t

V Q11satlV

FuV Vsatu C satu DV

FlV

SV+

Phase 1Ι

FastCurrent

Decay byInhibitSlow

Current Decay

Operating Conditions:V S = 40 VV = 5 VΙ

phase 1L

phase 1RΙ 1X

= 20= L;

V+ SQ12V

= 10 mHΩ1XΙ = H

t

t

t

t

t

t


TCA 3727

Calculation of Power Dissipation

The total power dissipation Ptot is made up ofsaturation losses Psat (transistor saturation voltage and diode forward voltages),quiescent losses Pq (quiescent current times supply voltage) andswitching losses Ps (turn-ON / turn-OFF operations).

The following equations give the power dissipation for chopper operation without phasereversal. This is the worst case, because full current flows for the entire time andswitching losses occur in addition.

Ptot = 2 × Psat + Pq + 2 × Ps

where Psat ≅ IN Vsatl × d + VFu (1 – d ) + VsatuC × d + VsatuD (1 – d )

Pq = Iq × VS + IL × VL

IN = nominal current (mean value)Iq = quiescent currentiD = reverse current during turn-on delayiR = peak reverse currenttp = conducting time of chopper transistortON = turn-ON timetOFF = turn-OFF timetDON = turn-ON delaytDOFF = turn-OFFdelayT = cycle durationd = duty cycle tp/TVsatl = saturation voltage of sink transistor (T3, T4)VsatuC = saturation voltage of source transistor (T1, T2) during charge cycleVsatuD = saturation voltage of source transistor (T1, T2) during discharge cycleVFu = forward voltage of free-wheeling diode (D1, D2)VS = supply voltageVL = logic supply voltageIL = current from logic supply

PS

VS

T------

iD tDON×2

----------------------iD iR+ tON×

4------------------------------

IN

2-----tDOFF tOFF++ +

≅


TCA 3727

Figure 12

Figure 13

Dx3 Dx4

Dx1 Dx2

V S+

Tx3

Tx1

Tx4

Tx2

L

V sense

senseR

IES01179

IET01210

Voltage andCurrent atChopperTransistor

t D t ON OFFtOFFt

pt

Vsatl

VS FuV+

i D

i RΙ N

Turn-ON Turn-OFF

+VFuSV

tDON


TCA 3727

Application Hints

The TCA 3727 is intended to drive both phases of a stepper motor. Special care hasbeen taken to provide high efficiency, robustness and to minimize external components.

Power Supply

The TCA 3727 will work with supply voltages ranging from 5 V to 50 V at pin Vs. As thecircuit operates with chopper regulation of the current, interference generation problemscan arise in some applications. Therefore the power supply should be decoupled by a0.22 µF ceramic capacitor located near the package. Unstabilized supplies may evenafford higher capacities.

Current Sensing

The current in the windings of the stepper motor is sensed by the voltage drop across R1and R2. Depending on the selected current internal comparators will turn off the sinktransistor as soon as the voltage drop reaches certain thresholds (typical 0 V, 0.25 V,0.5 V and 0.75 V); (R1 , R2 = 1 Ω). These thresholds are neither affected by variations ofVL nor by variations of VS.

Due to chopper control fast current rises (up to 10 A/µs) will occure at the sensingresistors R1 and R2. To prevent malfunction of the current sensing mechanism R1 and R2should be pure ohmic. The resistors should be wired to GND as directly as possible.Capacitive loads such as long cables (with high wire to wire capacity) to the motor shouldbe avoided for the same reason.

Synchronizing Several Choppers

In some applications synchrone chopping of several stepper motor drivers may bedesireable to reduce acoustic interference. This can be done by forcing the oscillator ofthe TCA 3727 by a pulse generator overdriving the oscillator loading currents(approximately Š± 100 µA). In these applications low level should be between 0 V and1 V while high level should be between 2.6 V and VL.

Optimizing Noise Immunity

Unused inputs should always be wired to proper voltage levels in order to obtain highestpossible noise immunity.

To prevent crossconduction of the output stages the TCA 3727 uses a special breakbefore make timing of the power transistors. This timing circuit can be triggered by shortglitches (some hundred nanoseconds) at the Phase inputs causing the output stage tobecome high resistive during some microseconds. This will lead to a fast current decayduring that time. To achieve maximum current accuracy such glitches at the Phaseinputs should be avoided by proper control signals.


TCA 3727

Thermal Shut Down

To protect the circuit against thermal destruction, thermal shut down has beenimplemented. To provide a warning in critical applications, the current of the sensingelement is wired to input Inhibit. Before thermal shut down occures Inhibit will start to pulldown by some hundred microamperes. This current can be sensed to build atemperature prealarm.


TCA 3727

Package Outlines

P-DSO-24-3(Plastic Dual Small Outline Package)

15.6-0.4

24 13

1 12

Index Marking

1)

1.272)0.35 +0.15

0.2 24x-0

.2

2.65

max

0.1

0.2

-0.1

2.45

1)-0.27.6

0.35 x 45˚

8˚ m

ax

0.23

+0.0

9

10.3 ±0.3

0.4 +0.8

1) Does not include plastic or metal protrusions of 0.15 max rer side2) Does not include dambar protrusion of 0.05 max per side GPS05144

Sorts of PackingPackage outlines for tubes, trays etc. are contained in our Data Book “Package Information”.

Dimensions in mmSMD = Surface Mounted Device


TCA 3727

Sorts of PackingPackage outlines for tubes, trays etc. are contained in our Data Book “Package Information”. Dimensions in mm

P-DIP-20-6(Plastic Dual In-line Package)

GP

D05

587


2-phase stepper-motor driver tca 3727 - cogumelo hobby · semiconductor group 1 1998-02-01 2-phase...

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