NJM3773

Figure 1. Block diagram

RC

NJM3773

M

A1

M

B1

M

B2

GND

V

R2

V

CC

C

1

V

R1

Phase

1

V

CC

S

R

Q

+

–

Logic

S

R

Q

+

–

Logic

+

–

Dis

1

Dis

2

NJM3773FM2

NJM3773E3

NJM3773D2

The NJM3773 is a switch-mode (chopper), constant-current

driver with two channels: one for each winding of a two-phase

stepper motor. The NJM3773 is also equipped with a Disable

input to simplify half-stepping operation. The circuit is well

suited for microstepping applications together with an external

micro controller. The current control inputs are low current,

high impedance inputs, which allows the use of unbuffered

DAC or external high resistive resistor divider network. The

NJM3773 contains a clock oscillator, which is common for

both driver channels, a set of comparators and flip-flops

implementing the switching control, and two output H-bridges,

including recirculation diodes. Voltage supply requirements

are +5 V for logic and +10 to +45 V for the motor. Maximum

output current is 750mA per channel.

s FEATURES

• Dual chopper driver

• 750 mA continuous output current per channel

• High impedance current control inputs

• Digital filter on chip eliminates external filtering components

• Packages DIP22 / PLCC28 / EMP24(Batwing)

DUAL STEPPER MOTOR DRIVER

s GENERAL DESCRIPTION

s PACKAGE OUTLINE