Datasheet A2918EWH, A2918SWV, A2918SWH, A2918EWV Datasheet (Allegro)

DISCONTINUED PRODUCT

— FOR REFERENCE ONLY.

Use UDN2917EB for new design

The A2918SWH and A2918SWV motor drivers are designed
to drive both windings of a bipolar stepper motor or bidirectionally
control two dc motors. All bridges are capable of sustaining 45 V and
include internal pulse-width modulation (PWM) control of the output
current to 1.5 A.

For PWM current control, the maximum output current is
determined by the user’s selection of a reference voltage and sensing
resistor. A PHASE input to each bridge determines load current
direction. Active low ENABLE inputs control the four drivers in
each bridge.

The bridges include both ground clamp and flyback diodes for
protection against inductive transients. Internally generated delays
prevent cross-over currents when switching current direction.
Special power-up sequencing is not required. Thermal protection
circuitry disables the outputs if the chip temperature exceeds safe
operating limits.

The A2918SWH/V are supplied in an 18-lead power-tab package
with staggered lead forming. The tab is internally insulated from the
device and requires no external isolation. The A2918SWH/V are
available for operation from -40°C to +85°C. To order, change the
suffix from 'S–' to 'E–'. These devices are also available on special
order for operation to +125°C.

FEATURES

■ ±1.5 A Continuous Output Current

■ 45 V Output Sustaining Voltage

■ Internal PWM Current Control

■ Low Output Saturation Voltage

■ Internal Clamp Diodes

■ Internal Thermal Shutdown Circuitry

■ Similar to Dual PBL3718 or Dual PBL3770

DUAL FULL-BRIDGE

PWM MOTOR DRIVER

ABSOLUTE MAXIMUM RATINGS

at TJ ≤ +150°C

Motor Supply Voltage, VBB. . . . . . . . . 45 V

Output Current, I

OUT

(tw≤20 µs) . . ±1.75 A

(Continuous) . . . . . . . . . . . . . .

±1.5 A

Logic Supply Voltage, VCC. . . . . . . . . 7.0 V

Logic Input Voltage Range,

V

IN

. . . . . . . . . . . . . . . -0.3 V to +7.0 V

Output Emitter Voltage, VE. . . . . . . . . 1.5 V

Package Power Dissipation,

P

D

. . . . . . . . . . . . . . . . . . . . See Graph

Operating Temperature Range,

T

A

. . . . . . . . . . . . . . . . -20°C to +85°C

Storage Temperature Range,

T

S

. . . . . . . . . . . . . . . -40°C to +150°C

Output current rating may be limited by duty cycle,
ambient temperature, and heat sinking. Under
any set of conditions, do not exceed the specified
peak current rating or a junction temperature of
+150°C.

Always order by complete part number:

Part Number Application

A2918SWH For Horizontal Mount

A2918SWV For Vertical Mount

V

REF

V

CC

V

BB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

1

2

PWM 1

PWM 2

TSD

Dwg. PP-051

OUT

1A

OUT

1B

OUT

2A

OUT

2B

E

1

E

2

SENSE

1

SENSE

2

GROUND

REFERENCE

LOGIC SPLY

LOAD SPLY

ENABLE

1

ENABLE

2

RC

1

RC

2

PHASE

1

PHASE

2

Data Sheet

29319.24A

2918

2918

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

FUNCTIONAL BLOCK DIAGRAM

TRUTH TABLE

Enable Phase Out

A

Out

B

LHHL
LLLH

HXZ Z

X = Don’t care
Z = High impedance

V

REF

V

CC

OUT

1A

OUT

1B

OUT

2A

OUT

2B

E

1

E

2

SENSE

1

SENSE

2

GROUND

REFERENCE

LOGIC

SUPPLY

LOAD

SUPPLY

ENABLE

1

ENABLE

2

RC

1

RC

2

PHASE

1

PHASE

2

V

BB

1

–
+

ONE SHOT

SOURCE
DISABLE

÷10

–
+

SOURCE
DISABLE

÷10

2

ONE SHOT

PWM 1

PWM 2

TSD

1816

12

14

13

117 5 2

4

15 10 3 6

8

7

9

11

R

T

R

S

R

S

R

T

R

C

C

T

C

T

C

C

R

C

C

C

Dwg. FP-033

50 75 100 125 150

10

6

4

2

0

ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS

TEMPERATURE IN °C

8

25

Dwg. GP-043

R

= 28

°C

/W

θ

J

A

R = 9

°C/W

θ

J

T

W
Copyright © 1991, 1993, Allegro MicroSystems, Inc.

2918

DUAL FULL-BRIDGE

PWM MOTOR DRIVER

www.allegromicro.com

ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 45 V, VCC = 4.75 V to 5.25 V,
V

REF

= 5.0 V (unless otherwise noted).

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Output Drivers (OUT

A

or OUTB)

Motor Supply Range V

BB

10 — 45 V

Output Leakage Current I

CEX

V

OUT

= V

BB

— <1.0 50 µA

V

OUT

= 0 — <-1.0 -50 µA

Output Sustaining Voltage V

CE(sus)

I

OUT

= ±1.5 A, L = 3.0 mH 45 — — V

Output Saturation Voltage V

CE(SAT)

Sink Driver, I

OUT

= +1.0 A — 0.7 0.8 V

Sink Driver, I

OUT

= +1.5 A — 0.9 1.1 V

Source Driver, I

OUT

= -1.0 A — 1.8 2.0 V

Source Driver, I

OUT

= -1.5 A — 1.9 2.2 V

Clamp Diode Leakage Current I

R

VR = 45 V — <1.0 50 µA

Clamp Diode Forward Voltage V

F

IF = 1.5 A — 1.6 2.0 V

Driver Supply Current I

BB(ON)

Both Bridges ON, No Load — 12 15 mA

I

BB(OFF)

Both Bridges OFF — 8.0 10 mA

Control Logic

Input Voltage V

IN(1)

All Inputs 2.4 — — V

V

IN(0)

All Inputs — — 0.8 V

Input Current I

IN(1)

V

IN

= 2.4 V — <1.0 20 µA

I

IN(0)

VIN = 0.8 V — -3.0 -200 µA

Reference Voltage Range V

REF

Operating 1.5 — V

CC

V

Current Limit Threshold V

REF/VSENSE

At Trip Point 9.5 10 10.5 —

Thermal Shutdown Temp. T

J

— 170 — °C

Total Logic Supply Current I

CC(ON)

VEN = 0.8 V, No Load — 105 140 mA

I

CC(OFF)

VEN = 2.4 V, No Load — 10 12 mA

Negative current is defined as coming out of (sourcing) the specified device pin.

Typical Data is for design information only.

2918

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

PWM OUTPUT CURRENT WAVEFORM

APPLICATIONS INFORMATION

PWM Current Control

The A2918SWH/V dual bridges are
designed to drive both windings of a bipolar stepper
motor. Output current is sensed and controlled
independently in each bridge by an external sense
resistor (RS), an internal comparator, and an internal
monostable multivibrator.

When the bridge is turned ON, current increases
in the motor winding and it is sensed by RS until the
sense voltage (V

SENSE

) reaches the level set at the

comparator’s input:

I

TRIP

= V

REF

/10 R

S

The comparator then triggers the monostable which
turns OFF the source driver of the bridge. The actual
load current peak will be slightly higher than the trip
point (especially for low-inductance loads) because of
internal logic and switching delays. This delay (td) is
2 µs typically. After turn-off, the motor current decays,
circulating through the ground clamp diode and sink
transistor. The source driver’s OFF time t

off

, and
therefore the magnitude of the current decrease, is
determined by the monostable’s external RC timing
components, where t

off

= RTCT within the range of 20

kΩ to 100 kΩ and 200 pF to 500 pF.

When the source driver is re-enabled, the winding
current (the sense voltage) again is allowed to rise to
the comparator’s threshold. This cycle repeats itself,
maintaining the average motor winding current at the
desired level.

Special circuitry has been included to prevent
runaway current control when t

off

is set too short.
This circuitry prevents the source driver from being
re-enabled until the load current has decayed to
below the I

TRIP

level.

Loads with high distributed capacitances may result
in high turn-ON current peaks. This peak, appearing
across RS, will attempt to trip the comparator, resulting
in possible erroneous current control or high-frequency
oscillations. An external RCCC low-pass filter may be
used to delay the action of the comparator, and thus
ignore turn-on spikes.

+

–

0

Dwg. WM-003-1A

V

PHASE

I

OUT

t

d

t

off

I

TRIP

2918

DUAL FULL-BRIDGE

PWM MOTOR DRIVER

www.allegromicro.com

LOAD CURRENT PATHSGeneral

To avoid excessive voltage spikes on the
LOAD SUPPLY pin (VBB), a large-value
capacitor (≥47 µF) should be connected from
VBB to the ground pin as close as possible to
the device. Under no circumstances should
the voltage at VBB exceed 45 V.

The PHASE input to each bridge
determines the direction motor winding
current flows. An internally generated
deadtime, of approximately 3 µs, prevents
crossover currents that can occur when
switching the PHASE input.

All four drivers in the bridge output can
be turned OFF, with VEN ≥ 2.4, resulting in
a fast current decay through the internal
ground clamp and flyback diodes. The fast
current decay is desirable in half-step and
high-speed applications. The ENABLE input
must be tied low if it is not used.

Varying the reference voltage (V

REF

)
provides continuous control of the peak load
current.

Thermal protection circuitry turns OFF all
drivers when the junction temperature
reaches approximately +170°C. It is
intended only to protect the device from
failures due to excessive junction
temperature and should not imply that output
short circuits are permitted. The output
drivers are re-enabled when the junction
temperature cools to approximately +145°C.

Dwg. EP-006-1

R

S

BB

V

BRIDGE ON
SOURCE OFF
ALL OFF

The products described here are manufactured in Japan by Sanken

Electric Co., Ltd. for sale by Allegro MicroSystems, Inc.

Sanken Electric Co., Ltd. and Allegro MicroSystems, Inc. reserve the
right to make, from time to time, such departures from the detail
specifications as may be required to permit improvements in the
performance, reliability, or manufacturability of their products.
Therefore, the user is cautioned to verify that the information in this
publication is current before placing any order.

These products are not authorized for use as critical components in
life-support appliances, devices, or systems without express written
approval.

The information included herein is believed to be accurate and
reliable. However, Sanken Electric Co., Ltd. and Allegro
MicroSystems, Inc. assume no responsibility for its use; nor for any
infringements of patents or other rights of third parties which may
result from its use.

2918

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

1

18

1.228

1.213

0.066 ±0.016

0.637

0.623

0.196

0.182

0.126 x 0.150

Dwg. MP-006 in

0.968

0.953

0.070

0.063

0.022

0.033

0.022

0.131

0.120

0.519

0.504

0.397

0.382

0.091

0.083

0.260

0.213

0.318

0.272

0.141

0.095

0.204

0.158

0.086

0.040

ø

0.653

0.638

1.240

1.225

A2918SWH for horizontal mounting

Dimensions in Inches

(for reference only)

Dimensions in Millimeters

(controlling dimensions)

NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.

2. Lead spacing tolerance is non-cumulative.

1

18

16.6

16.2

31.2

30.8

31.5

31.1

1.68 ±0.4

16.2

15.8

5.0

4.6

3.2 x 3.8

Dwg. MP-006 mm

24.6

24.2

1.8

1.6

0.57

0.54

0.85

0.55

3.35

3.05

∅

13.2

12.8

2.3

2.1

6.6

5.4

8.1

6.9

3.6

2.4

5.2

4.0

2.2

1.0

10.1

9.7

2918

DUAL FULL-BRIDGE

PWM MOTOR DRIVER

www.allegromicro.com

A2918SWV for vertical mounting

Dimensions in Inches

(for reference only)

Dimensions in Millimeters

(controlling dimensions)

NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.

2. Lead spacing tolerance is non-cumulative.

118

0.653

0.638

1.228

1.213

1.240

1.225

0.066 ±0.027

0.637

0.623

0.196

0.182

0.185

0.130

0.126 x 0.150

Dwg. MP-004 in

0.968

0.953

0.070

0.063

0.022

0.033

0.022

0.131

0.120

∅

0.104

0.089

0.519

0.504

0.283

0.245

0.421

0.363

0.397

0.382

118

16.6

16.2

31.2

30.8

31.5

31.1

1.68 ±0.7

16.2

15.8

5.0

4.6

4.7

3.3

3.2 x 3.8

Dwg. MP-004 mm

24.6

24.2

1.8

1.6

0.57

0.54

0.85

0.55

3.35

3.05

∅

7.2

6.2

2.65

2.25

13.2

12.8

10.7

9.2

10.1

9.7

2918

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

MOTOR DRIVERS

Function Output Ratings* Part Number

†

INTEGRATED CIRCUITS FOR BRUSHLESS DC MOTORS

3-Phase Power MOSFET Controller — 28 V 3933
3-Phase Power MOSFET Controller — 50 V 3932
3-Phase Power MOSFET Controller — 50 V 7600
2-Phase Hall-Effect Sensor/Driver 400 mA 26 V 3626
Bidirectional 3-Phase Back-EMF Controller/Driver ±600 mA 14 V 8906
2-Phase Hall-Effect Sensor/Driver 900 mA 14 V 3625
3-Phase Back-EMF Controller/Driver ±900 mA 14 V 8902–A
3-Phase Controller/Drivers ±2.0 A 45 V 2936 & 2936-120

INTEGRATED BRIDGE DRIVERS FOR DC AND BIPOLAR STEPPER MOTORS

Dual Full Bridge with Protection & Diagnostics ±500 mA 30 V 3976
PWM Current-Controlled Dual Full Bridge ±650 mA 30 V 3966
PWM Current-Controlled Dual Full Bridge ±650 mA 30 V 3968
PWM Current-Controlled Dual Full Bridge ±750 mA 45 V 2916
PWM Current-Controlled Dual Full Bridge ±750 mA 45 V 2919
PWM Current-Controlled Dual Full Bridge ±750 mA 45 V 6219
PWM Current-Controlled Dual Full Bridge ±800 mA 33 V 3964
PWM Current-Controlled Full Bridge ±1.3 A 50 V 3953
PWM Current-Controlled Dual Full Bridge ±1.5 A 45 V 2917
PWM Current-Controlled Microstepping Full Bridge ±1.5 A 50 V 3955
PWM Current-Controlled Microstepping Full Bridge ±1.5 A 50 V 3957
PWM Current-Controlled Dual DMOS Full Bridge ±1.5 A 50 V 3972
Dual Full-Bridge Driver ±2.0 A 50 V 2998
PWM Current-Controlled Full Bridge ±2.0 A 50 V 3952
DMOS Full Bridge PWM Driver ±2.0 A 50 V 3958
Dual DMOS Full Bridge ±2.5 A 50 V 3971

UNIPOLAR STEPPER MOTOR & OTHER DRIVERS

Voice-Coil Motor Driver ±500 mA 6 V 8932–A
Voice-Coil Motor Driver ±800 mA 16 V 8958
Unipolar Stepper-Motor Quad Drivers 1 A 46 V 7024 & 7029
Unipolar Microstepper-Motor Quad Driver 1.2 A 46 V 7042
Unipolar Stepper-Motor Translator/Driver 1.25 A 50 V 5804
Unipolar Stepper-Motor Quad Driver 1.8 A 50 V 2540
Unipolar Stepper-Motor Quad Driver 1.8 A 50 V 2544
Unipolar Stepper-Motor Quad Driver 3 A 46 V 7026

Unipolar Microstepper-Motor Quad Driver 3 A 46 V 7044

* Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits or

over-current protection voltage limits. Negative current is defined as coming out of (sourcing) the output.

† Complete part number includes additional characters to indicate operating temperature range and package style.

Also, see 3175, 3177, 3235, and 3275 Hall-effect sensors for use with brushless dc motors.