PBL 3771/1

4

C

MM2

E

B2

B1

GND

MM1

C

RC

V

5

6

7

8

9

10

11

25

24

23

22

21

20

19

CC

V

M

M

V

2

1

2

PBL 3771/1QN

1

2

3

4

5

6

7

8

9

10

11

22

21

20

19

18

17

16

15

14

13

12

B1

E

MM1

A1

GND

GND

1

1

R1

C

CC

M

V

M

GND

GND

Phase

CD

V

RC

M

V

M

Phase

CD

V

V

R2

2

2

A2

MM2

B2

1

1

PBL

3771/1N

Figure 4. Pin configuration.

Pin Description

Refer to figure 4.

SO

DIP

PLCC

Symbol

Description

21

8

M

B1

Motor output B, channel 1. Motor current flows from M

32

10

E

1

Common emitter, channel 1. This pin connects to a sensing resistor to ground.

43

11

V

MM1

Motor supply voltage, channel 1, 10 to 40 V. V

54

12

M

A1

Motor output A, channel 1. Motor current flows from M

6,7,

5,6,

1-3,9,

GND

Ground and negative supply. Note: these pins are used thermally for heat-sinking.

18,19

17,18

13-17,28

Make sure that all ground pins are soldered onto a suitably large copper ground

plane for efficient heat sinking.

8

7

18

Phase

1

Controls the direction of motor current at outputs M

to M

98

19

CD

1

Current decay control, channel 1. A logic HIGH on this input results in

slow current decay,

a LOW results in

fast current decay, see “Functional Description.”

10

9

20

V

R1

Reference voltage, channel 1. Controls the threshold voltage for the comparator and hence

the output current. Input resistance is typically 2.5 kohms,

±20%.

11

10

21

C

1

Comparator input channel 1. This input senses the instantaneous voltage across the

sensing resistor, filtered by an RC network. The threshold voltage for the comparator is

(0.450 / 2.5) • V

12

11

22

V

CC

Logic voltage supply, nominally +5 V.

13

12

23

RC

Clock oscillator RC pin. Connect a 15 kohm resistor to V

ground to obtain the nominal switching frequency of 26.5 kHz.

14

13

24

C

2

Comparator input channel 2. This input senses the instantaneous voltage across the

sensing resistor, filtered by an RC network. The threshold voltage for the comparator is

(0.450 / 2.5) • V

15

14

25

V

R2

Reference voltage, channel 2. Controls the threshold voltage for the comparator and hence

the output current. Input resistance is typically 2.5 kohms,

±20%.

16

15

26

CD

2

Current decay control, channel 2. A logic HIGH on this input results in

slow current decay,

a LOW results in

fast current decay, see “Functional Description.”

17

16

27

Phase

2

Controls the direction of motor current at outputs M

to M

20

19

4

M

A2

Motor output A, channel 2. Motor current flows from M

21

20

5

V

MM2

Motor supply voltage, channel 2, 10 to 40 V. V

22

21

6

E

2

Common emitter, channel 2. This pin connects to a sensing resistor to ground.

23

22

7

M

B2

Motor output B, channel 2. Motor current flows from M

1

2

3

4

5

6

8

9

10

11

22

21

20

19

18

17

16

15

14

13

12

GND

GND

NC

PBL

3771/1 SO

NC

V

cc

RC

23

24

GND

GND

7