NJM3777
DUAL STEPPER MOTOR DRIVER
s
GENERAL DESCRIPTION
s
PACKAGE OUTLINE
The NJM3777 is a switch-mode (chopper), constant-current
driver with two channels: one for each winding of a two-phase
stepper motor. The NJM3777 is equipped with a Disable input
to simplify half-stepping operation. The NJM3777 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
NJM3777E3
diodes. Voltage supply requirements are + 5 V for logic and +
10 to + 45 V for the motor. Maximum output current is 900mA
per channel.
s
FEATURES
• Dual chopper driver
• 900 mA continuous output current per channel
• Digital filter on chip eliminates external filtering components
• Package
EMP24(Batwing)
s
BLOCK DIAGRAM
Phase
1
Dis
1
V
R1
C
1
E
1
NJM3777
V
CC
V
–
+
CC
R
S
Q
M
A1
Logic
M
B1
V
MM1
+
–
V
MM2
M
B2
Logic
M
A2
RC
+
–
S
R
Q
Phase
2
Dis
2
V
R2
C
2
GND
E
2
Figure 1. Block diagram