PBL3770A Datasheet, PDF (1/8 Pages) Ericsson – High Performance Stepper Motor Drive Circuit

February 1999
PBL 3770A
High Performance
Stepper Motor Drive Circuit
Description
PBL 3770A is a bipolar monolithic circuit intended to control and drive the current in
one winding of a stepper motor. It is a high power version of PBL 3717 and special
care has been taken to optimize the power handling capability without suffering in
reliability.
The circuit consists of a LS-TTL compatible logic input stage, a current sensor, a
monostable multivibrator and a high power H-bridge output stage. The circuit is
pin-compatible with the PBL 3717 industry-standard driver.
Two PBL 3770A and a small number of external components form a complete
control and drive unit for LS-TTL or microprocessor-controlled stepper motor
systems.
Key Features
• Half-step and full-step operation.
• Switched mode bipolar constant
current drive
• Wide range of current control
5 -1800 mA.
• Wide voltage range 10 - 45 V.
• Designed for unstabilized motor
supply voltage.
• Current levels can be selected in
steps or varied continuously.
• Thermal overload protection.
Phase
I
1
I₀
V_R
GND
V_CC
V_MM
V_MM
Schmitt
Trigger
Time
Delay
1
≥1
≥1
M_A
M_B
&&&&
≥1
≥1
+
–
+
–
+
–
Current Sensor
C
Output Stage
Monostable
t_off = 0.69 • R_T • C_T
T
E
PBL 3770A
Figure 1. Block diagram.
PBL3770A
377P0ABL
PBL ^3770A
16-pin plastic batwing DIP
28-pin plastic PLCC package
20-pin SO
1