NJM3773
DUAL STEPPER MOTOR DRIVER
s GENERAL DESCRIPTION
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 PACKAGE OUTLINE
NJM3773D2
NJM3773E3
(SOP24 JEDEC 300mil )
(DIP22)
NJM3773FM2
(PLCC28)
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 / SOP24 JEDEC 300mil (Batwing)
s BLOCK DIAGRAM
Phase 1
Dis1 VR1
E1
C1
NJM3773
VCC
–
V
CC
+
R
S
Q
M A1
M B1
Logic
V MM1
+
V MM2
–
M B2
Logic
M A2
RC
+
–
Phase 2
Figure 1. Block diagram
Dis 2 V
R2
C2
S
R
GND
Q
E2
