3951

FULL-BRIDGE

PWM MOTOR DRIVER

9

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Typical Bipolar Stepper Motor Application

For both cases, care must be taken to ensure that the

maximum current ratings of the device are not exceeded.

The load current will limit at a value

I

CAUTION: When the direction of the motor is changed

abruptly, the kinetic energy stored in the motor and load

inertia will be converted into current that charges the V

BB

supply bulk capacitance (power supply output and

decoupling capacitance). Care must be taken to ensure

the capacitance is sufficient to absorb the energy without

exceeding the voltage rating of any devices connected to

the motor supply.

See also, the section on brake operation under

“Functional Description”, above.

Stepper Motor Applications

The A3951SB and A3951SW may be used for

bidrectional control of bipolar stepper motors with continu-

ous output currents to 2 A and peak start-up currents as

high as 3.5 A.

Typical DC Servo Motor Application

+

V

BB

Dwg. EP-048-1

V

REF2

V

REF1

47

µF

+5 V

0.5

Ω

25 k

Ω

820 pF

LOGIC

LOGIC

47

µF

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

V

CC

LOGIC

Dwg. EP-047-1

V

BB

PHASE

ENABLE

+5 V