February 1999
PBL 3775/1
Dual Stepper Motor Driver
Description
The PBL 3775/1 is a switch-mode (chopper), constant-current driver IC with two
channels, one for each winding of a two-phase stepper motor. The circuit is similar to
Ericsson´s PBL 3773/1. While several of Ericsson´s dual stepper motor drivers are
optimized for micro-stepping applications, PBL 3775/1 is equipped with a disable
input to simplify half-stepping operation.
The PBL 3775/1 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.
The close match between the two driver channels guarantees consistent output
current ratios and motor positioning accuracy.
Key Features
• Dual chopper driver in a single
package.
• Operation down to -40°C.
• 750 mA continuous output current
per channel.
• Low power dissipation, 2.0 W at
2 x 500 mA output current.
• Close matching between channels
for high microstepping accuracy.
• Digital filter on chip eliminates
external filtering components.
• Plastic 22-pin batwing DIL package,
24-pin SOIC batwing or 28-pin power
PLCC. All with lead-frame for
heatsinking through PC board
copper.
V
CC
V
–
+
CC
R
S
Q
M
A1
P
PBL 3775/1
B
L
B /1
P 75
37
Logic
M
B1
V
MM1
V
MM2
M
B2
Logic
M
A2
+
–
+
–
L
RC
S
R
Q
Phase
2
Dis
2
V
R2
C
2
GND
E
2
37
28-pin PLCC package
22-pin plastic DIP package
24-pin SO package
Phase
1
Dis
1
V
R1
C
1
E
1
Figure 1. Block diagram
PB
L
37
75
/1
75
/1
ERICSSON [ ERICSSON ]
