Datasheet CS3717AGNF16 Datasheet (Cherry Semiconductor)

1

Features

■

Full/Half /Quarter Step
Operation

■

Output Current Up to 1 A

■

Motor Supply Voltage 10V
to 46V

■ Integrated Bootstrap

Lowers Saturation Voltage

■ Built In Protection Diodes

■ Externally Selectable

Current Level

■ Digital or Analog Control

of Output Current Level

■ Thermal Overload

Protection

■ Minimum External

Components

Package Options

CS3717A

1A H-Bridge Stepper Motor Driver

CS3717A

Description

The CS3717A controls and drives
one phase of a bipolar stepper
motor with chopper control of the
phase current. Current levels may
be selected in three steps by means
of two logic inputs which select one
of three current comparators. When
both of these inputs are high the
device is disabled. A separate logic
input controls the direction of cur­rent flow. A monostable, pro­grammed by an external RC net­work, sets the current decay time.

The power section is a full H-bridge

driver with four internal clamp
diodes for current recirculation. An
external connection to the lower
emitters is available for the inser­tion of a sensing resistor. Two
CS3717AÕs and several external
components form a complete step­per motor drive subsystem.

The recommended operating ambi­ent temperature range is from 0 to
70¡C.

The CS3717A is supplied in a 16
lead PDIP.

Block Diagram

16L PDIP

(Internally Fused Leads)

1

OUTB

Pulse

V

DD

B

Gnd

V

CC

IN1

DIRECTION

Sense

OUTA

V

DD

A

Gnd

Gnd

V

REF

Comp In

IN0

Gnd

Power Supply Voltage (V

DDA

, V

DDB

)............................................................50V

Logic Supply Voltage (VCC)..............................................................................7V

Logic Input Voltage (IN0, IN1, DIRECTION)................................................6V

Comparator Input............................................................................................V

CC

Reference Input Voltage..................................................................................15V

Output Current (DC Operation)...................................................................1.2A

Storage Temperature .................................................................Ð55¡C to +150¡C

Operating Junction Temperature.............................................Ð40¡C to +150¡C

Lead Temperature Soldering

Wave Solder(through hole styles only) ............10 sec. max, 260¡C peak

Absolute Maximum Ratings

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

¨

Rev. 4/29/99

IN0

DIRECTIONIN1

V

DD

OUTA

A

OUTB

V

DD

B

V

CC

V

REF

Gnd

6KW

223W

223W

105W

00 01 10 11

+

-

+

-

+

-

THERMAL

SHUTDOWN

MONO-

STABLE

PulseComp In Sense

2

Electrical Characteristics: Refer to the test circuit VDD= 36V, VCC= 5V, TA= 25¡C; unless otherwise specified.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS3717A

Supply Voltage 10 46 V
Logic Supply Voltage 4.75 5.25 V
Logic Supply Current 7 15 mA
Reference Input Current V

REF

= 5V 0.75 1.00 mA

■ Logic Inputs

Input Low Voltage 0.8 V

Input High Voltage 2 V
Low Voltage Input Current V

IN

= 0.4V (DIRECTION) -100 µA

(IN0, IN1) -400 µA

High Voltage Input Current VIN= 2.4V 10 µA

■ Comparators

Comparator Low V

REF

= 5V IN0 = Low 66 80 94 mV
Threshold Voltage IN1 = High
Comparator Medium V

REF

= 5V IN0 = High 236 251 266 mV
Threshold Voltage IN1 = Low
Comparator High V

REF

= 5V IN0 = Low 396 416 436 mV
Threshold Voltage IN1 = Low
Comparator Input Current ±20 µA
Cutoff Time R

T

= 56k½ CT= 820pF 27 37 µs

Turn Off Delay 2µs
Output Leakage Current IN0 =IN1 = High 100 µA

■ Source Diode-Transistor Pair

Saturation Voltage I

MOTOR

= -0.5A conduction period 1.7 2.1 V

recirculation period 1.10 1.35 V

Saturation Voltage I

MOTOR

= -1A conduction period 2.1 2.8 V

recirculation period 1.7 2.5 V

Leakage Current V

S

= 46V 300 µA

Diode Forward Voltage I

MOTOR

= -0.5A 1.00 1.25 V

I

MOTOR

= -1A 1.3 1.7 V

■ Sink Diode-Transistor Pair

Saturation Voltage I

MOTOR

= 0.5A 1.20 1.45 V

I

MOTOR

= 1A 1.75 2.30 V

Leakage Current V

S

= 46V 300 µA

Diode Forward Voltage I

MOTOR

= 0.5A 1.1 1.5 V

I

MOTOR

= 1A 1.4 2.0 V

3

Package Pin Description

PACKAGE PIN # PIN SYMBOL FUNCTION

CS3717A

Truth Table

IN0 IN1 Output Current

H H No Current

L H Low Current

H L Medium Current

L L High Current

16L

(Internally Fused Leads)

1 OUT B Output connection with OUTA. The output stage is a ÒHÓ bridge

formed by four transistors and four diodes suitable for switching
applications.

2 Pulse A parallel RC network connected to this pin sets the OFF time of

the lower power transistors. The pulse generator is a monostable
triggered by the rising edge of the output of the comparators
(t

OFF

= 0.69 RTCT).

3V

DDB

Supply voltage input for half output stage.

4, 5, 12, 13 Gnd Ground connection. Also conducts heat from die to printed

circuit copper.

6V

CC

Supply voltage input for logic circuitry.

7 IN1 This pin and IN0 are logic inputs which select the outputs of the

three comparators to set the current level. Current also depends on
the sensing resistor and reference voltage. See truth table.

8 DIRECTION This TTL-compatible logic input sets the direction of current

flow through the load. A high level causes current to flow from
OUTA (source) to OUTB (sink). A Schmitt trigger on this input
provides good noise immunity and a delay circuit prevents out­put stage short circuits during switching.

9 IN0 See IN1.

10

Comp In

Input connected to the three comparators. The voltage across the
sense resistor is fed back to this input through the low pass filter
RCCC. The lower power transistors are disabled when the sense
voltage exceeds the reference voltage of the selected comparator.
When this occurs the current decays for a time set by RTCT,
t

OFF

= 0.69 RTCT.

11 V

REF

A voltage applied to this pin sets the reference voltage of the
three comparators, thus determining the output current (also
dependent on R

Sense

and the two inputs IN 0 and IN 1).

14 V

DDA

Supply voltage input for half output stage.

15 OUT A See OUTB.

16 Sense Connection to lower emitters of output stage for insertion of

current sense resistor.

Control of the motor

The stepper motor can rotate in either direction according
to the sequence of the input signals. It is possible to obtain
a full step, a half step and quarter step operation.

Full step operation

Both windings of the stepper motor are energized all the
time with the same current IMA= IMB.

IN0 and IN1 remain fixed at whatever torque value is
required.

Calling A the condition with winding A energized in one
direction and A in the other direction, the sequence for
full step rotation is:

AB®AB®AB®AB etc.

4

Typical Performance Characteristics

Source Saturation Voltage vs. Output Current

(Conduction Period)

Source Saturation Voltage vs. Output Current

(Recirculation Period)

CS3717A

Comparator Threshold vs. Junction TemperatureSink Saturation Voltage vs. Output Current

The application diagram shows a typical application in
which two CS3717A's control a two phase bipolar stepper
motor.

Programming

The amplitude of the current flowing in the motor wind­ing is controlled by the logic inputs IN0 and IN1. The
truth table (page 3) shows three current levels and an off
state. A high level on the ÒDirectionÓ logic input sets the
direction of that current from OUTA to OUTB; a low level
from OUTB to OUTA.

It is recommended that unused inputs are tied to VCCor
(Gnd) as appropriate to avoid noise problems.

The current levels can be varied continuously by changing
V

REF

.

Application Information

SAT (V)

CE

V

4

3

2

1

0

0.2 0.4 0.6 0.8

I (A)

4

SAT (V)

CE

V

4

3

2

1

0

0.2 0.4 0.6 0.8
I (A)

3

(V)

SAT

2

V

1

0

0.2 0.4 0.6 0.8

I (A)

100

80

(%)

60

CX

V

40

20

0

60 80 100 120 14020

40 160

TJ (C)

For rotation in the other direction the sequence must be
reversed.

The torque of each step is constant in full step operation.

Half step operation

Power is applied alternately to one winding then both
according to the sequence:

AB®B®AB®A®AB®B®AB®A etc.

Like full step this can be done at any current level; the
torque is not constant but is lower when only one winding
is energized.

A coil is turned off by setting IN0 and IN1 both high.

Quarter step operation

It is preferable to realize the quarter step operation at full
power otherwise the steps will be of very irregular size.

The extra quarter steps are added to the half step
sequence by putting one coil on half current according to
the sequence.

AB®AB®B®AB®AB®AB®A etc.

2 2 2

Motor selection

As the CS3717A provides constant current drive with a
switching operation, care must be taken to select stepper
motors with low hysteresis losses to prevent motor over­heating.

L-C filter

To reduce EMI and chopping losses in the motor, a low
pass L-C filter can be inserted across the outputs of the
CS3717A as shown in the following diagram.

5

Application Information: continued

Input and Output Sequences for Half Step and Full Step Operation

CS3717A

OUTA

CS3717A

OUTB

L

MOTOR

C

WINDING
(L

, RM)

M

STAND BY WITH

HOLDING TORQUE

1M = 80mA

DIRECTION

IN

DIRECTION

OUT

- 500 mA

IN0
IN1

IN0
IN1

500 mA

I

MA

500 mA

1

L @ L

A
A

A
B

B
B

M

10

HALF STEP MOTOR DRIVE

12345678

1M = 250mA

C @

10

4 ¥ 10

L

FULL STEP MOTOR DRIVE

1M = 500mA

I

MB

- 500 mA

6

Test Circuit

Waveforms with MA Regulating (Phase = 0)

CS3717A

Logic

Control

Inputs

Motor

Supply

+36V

A

R

1kW

V

OUTA

OUTB

SenseComp InGndPulse

C

DD

V

DD

V

C

C

C

820 pF

Gnd

Reference

Voltage

+5V

V

REF

IN1

IN0

DIRECTION

T

Logic

Supply

+5V

CS3717A

R

T

56kW

V

CC

C

820 pF

V

B

RS

R

1W

SENSE

L

L @ 10mH
R @ 13W

Motor

Winding

V

SENSE

V

Comp In

V

OUT A

V

OUT B

V

CX

0V

T

V

CX

D

0V

V

DD

V

V

SAT

F

0V

V

SAT REC

V

CC

V

SAT COND

t

t

t

V

MOTOR

0V

T

ON

T

OFF

t

7

Application Circuit - Two Phase Bipolar Stepper Motor Driver

CS3717A

The R

QJA

of the CS3717A can be reduced by soldering the
Gnd pins to a suitable copper area of the printed circuit
board or to an external heatsink.

The diagram of fig. 2 shows the maximum dissipated
power P

tot

and the R

QJA

as a function of the side Òl Ó of

two equal square copper areas having a thickness of 35µ

(see fig. 1). In addition, it is possible to use an external
heatsink (see fig. 3). During soldering the pins temperature
must not exceed 260ûC and the soldering time must not be
longer than 12 seconds.

The external heatsink or printed circuit copper area must
be connected to electrical ground.

Mounting Instructions

Figure 2 - Max. Power Dissipation And Junction To Ambient Thermal
Resistance vs. Size ÒlÓ for 16 lead fused package.

1

2

3

4

P

tot

(W)

10 20 30 40 I(mm)

0

0

20

40

60

80

(ûC/W)

0

ÒlÓ

P

tot

(T

amb

= 70ûC)

R

q JA

R

q JA

l

l

COPPER AREA 35m THICKNESS

P.C. BOARD

Figure 1 - Example of P.C. Board Copper Area Which is Used as
Heatsink with 16 lead fused package.

170mm

38.0mm

11.9mm

0

-50

1

2

3

4

5

P

tot

(W)

0

50 100

T

amb

(C)

FREE AIR

HEAT - SINK WITH R

th

= 25ûC/W

WITH INFINITE HEAT - SINK

Figure 3 - External Heatsink Mounting Example (Rth= 30ûC/W) for 16
lead batwing package.

Figure 4 - Maximum Allowable Power Dissipation vs. Ambient
Temperature for 16 lead batwing package.

FROM

m PROCESSOR

0.1mF

R

T

56kW

R

T

56kW

C3

IN1

IN0

DIRECTION
Pulse

Pulse

DIRECTION

IN1

IN0

V

V

V

REF

C

T

820pF

C

T

820pF

REF

V

DD

V

R

1kW

C

C

820pF

C

C

820pF

R

1kW

V

S

C1 100mF

C2

0.1mF

V

DD

A

B

OUTA

OUTB

SenseGnd

C

C

Sense

Out B

OutA

V

DD

DD

A

B

1W

R

1W

R

Sense

Sense

MAA

MBA

I

MA

I

MB

STEPPER

MOTOR

SS

V

CC

CS3717A

CS-3717A

Gnd

COMP IN

Gnd

Gnd

Comp In

CS3717A

V

CC

Part Number Description

CS3717AGNF16 16 Lead PDIP

(Internally Fused Leads)

D

Lead Count Metric English

Max Min Max Min

16L PDIP 19.69 18.67 .775 .735

(Internally Fused Leads)

8

Rev. 4/29/99

16 Lead PDIP

Thermal Data (Internally Fused Leads)

R

QJC

typ 15 ûC/W

R

QJA

typ 50 ûC/W

Package Specification

PACKAGE DIMENSIONS IN mm (INCHES)

PACKAGE THERMAL DATA

Ordering Information

CS3717A

© 1999 Cherry Semiconductor Corporation

Cherry Semiconductor Corporation reserves the
right to make changes to the specifications without
notice. Please contact Cherry Semiconductor
Corporation for the latest available information.

Plastic DIP (N); 300 mil wide

0.39 (.015)
MIN.

2.54 (.100) BSC

1.77 (.070)

1.14 (.045)

D

Some 8 and 16 lead
packages may have
1/2 lead at the end
of the package.
All specs are the same.

.203 (.008)

.356 (.014)

REF: JEDEC MS-001

3.68 (.145)

2.92 (.115)

8.26 (.325)

7.62 (.300)

7.11 (.280)

6.10 (.240)

.356 (.014)

.558 (.022)