NJM3774

Figure 2. Pin configurations

C

E

B2

B1

GND

C

RC

V

5

6

7

8

9

10

11

25

24

23

22

21

20

19

CC

M

M

1

Phase

2

1

2

NJM3774FM2

1

2

3

4

5

6

7

8

9

10

11

22

21

20

19

18

17

16

15

14

13

12

C

R2

A1

GND

GND

1

R1

CC

M

V

M

GND

GND

Phase

Dis

RC

V

M

Phase

V

V

2

2

A2

MM2

B2

2

NJM

3774D2

s PIN CONFIGURATIONS

s PIN DESCRIPTION

PLCC

DIP

Symbol

Description

1-3, 9, 5, 6

GND

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

13-17 17, 18

ground pins are soldered onto a suitably large copper ground plane for efficient heat sinking.

28

48M

A2

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

59V

MM2

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

610

E

2

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

S

to ground.

711

M

B2

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

812

M

B1

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

10

13

E

1

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

S

to ground.

11

14

V

MM1

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

12

15

M

A1

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

18

16

Dis

1

Disable input (TTL level compatible) for channel 1. When HIGH, all four output transistors are turned

off, which results in a rapidly decreasing output current to zero.

19

19

Phase

1

Controls the direction of motor current at outputs M

when Phase

20

20

V

R1

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

current.

21

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 V

[V], i.e. 450

mV at V

22

22

V

CC

Logic voltage supply, nominally +5 V.

23

1

RC

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

the nominal switching frequency of 26.5 kHz.

24

2

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 V

[V], i.e. 450 mV

at V

25

3

V

R2

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

current.

26

4

Phase

2

Controls the direction of motor current at outputs M

when Phase

27

7

Dis

2

Disable input (TTL level compatible) for channel 2. When HIGH, all four output transistors are turned

off, which results in a rapidly decreasing output current to zero.