Stepper motor drivers are brushless DC motor drivers that can be used for both positioning and velocity control applications without the need for external position feedback. Typical stepper motors consist of a rotating permanent magnet (rotor) surrounded by electromagnets (stator). When the electromagnets are supplied current in the correct polarity and sequence a torque is created that moves the rotor in steps. These steps can be sequenced together to move the rotor at various speeds corresponding to the sequence rate. Positioning can be accomplished by controlling the number of sequenced steps.
By precisely controlling the current in each motor phase you can divide a motor’s fundamental step angle into smaller microsteps. Microstepping results in better positional resolution, less resonance issues and lower audible noise.
Allegro offers a complete lineup of stepper motor drivers for office automation, industrial, and automotive applications. Depending on the needs of a given application, Allegro IC solutions can include features such as:
- PWM current control
- Microstepping
- Parallel, Serial and Step/Direction interfaces
- Slow, Fast and Mixed current decay mode control
- Protection features – Under-voltage lockout, thermal shutdown, shoot through, overvoltage, over current protection
- Package options include exposed pad QFN, TSSOP, SOIC and DIP packages all lead (Pb) free
- Internal DMOS outputs or gate controllers to drive external MOSFETs
- Synchronous rectification
- Diagnostic outputs
- Stall detect assistance
Bipolar Stepper Motor Drivers Selection Guide
Step/Direction Interface |
Part Number |
Output Voltage Range (V) |
Output Current Range |
Interface |
Packages |
A4989 |
12 to 50 |
<10 A Typical (MOSFET gate driver IC) |
Parallel (Translator) |
TSSOP-38 |
A3981K |
7 to 50 |
1.4 A |
Parallel/SPI (Translator) |
eTSSOP-28 |
A4979 |
7 to 50 |
1.5 A |
SPI/Parallel (Translator) |
eTSSOP-28 |
A4980K |
3.3 to 50 |
1.4 A |
Parallel/SPI (Translator) |
eTSSOP-28 |
A3967 |
8 to 35 |
750 mA |
Parallel (Translator) |
SOIC-24 |
A3977 |
8 to 35 |
2.5 A |
Parallel (Translator) |
PLCC-44, eTSSOP-28 |
A3979 |
8 to 35 |
2.5 A |
Parallel (Translator) |
eTSSOP-28 |
A3982 |
8 to 35 |
1.5 A |
Parallel (Translator) |
SOIC-24 |
A3983 |
8 to 35 |
1.5 A |
Parallel (Translator) |
eTSSOP-24 |
A3984 |
8 to 35 |
1.5 A |
Parallel (Translator) |
eTSSOP-24 |
A3987 |
8 to 35 |
1.5 A |
Parallel (Translator) |
eTSSOP-24 |
A4982 |
8 to 35 |
2.0 A |
Parallel (Translator) |
QFN-32, eTSSOP-24 |
A4983 |
8 to 35 |
2.0 A |
Parallel (Translator) |
QFN-28 |
A4984 |
8 to 35 |
2.0 A |
Parallel (Translator) |
QFN-24, QFN-32, eTSSOP-24 |
A4985 |
8 to 35 |
1.0 A |
Parallel (Translator) |
QFN-24, QFN-32, eTSSOP-24 |
A4988 |
8 to 35 |
2.0 A |
Parallel (Translator) |
QFN-28 |
Parallel Interface (I0, I1) |
Part Number |
Output Voltage Range (V) |
Output Current Range |
Interface |
Packages |
A4975 |
5 to 50 |
1.5 A |
Parallel (I0, I1) |
DIP-16, SOIC-16 |
A4990K |
7 to 50 |
1.4 A |
Parallel (IN1-IN4) |
eTSSOP-20 |
A4970 |
10 to 45 |
750 mA |
Parallel (I0, I1) |
SOIC-24 |
A3988 |
8 to 36 |
1.2 A |
Parallel (I0, I1) |
QFN-36, eLQFP-48 |
A3989 |
8 to 35 |
1.2 A (Step), 2.4 A (DC) |
Parallel (I0, I1) |
QFN-36 |
A3995 |
8 to 35 |
2.4 A |
Parallel (I0, I1) |
QFN-36 |
A4986 |
8 to 35 |
2.0 A |
Parallel (I0, I1) |
eTSSOP-24 |
A4987 |
8 to 35 |
1.0 A |
Parallel (I0, I1) |
QFN-24, eTSSOP-24 |
A3966 |
4.5 to 30 |
650 mA |
Parallel (I0, I1) |
SOIC-16 |
A3906 |
2.5 to 9 |
1.0 A |
Parallel (I0, I1) |
QFN-20 |
A3901 |
2.5 to 5.5 |
400 mA |
Parallel (I0, I1) |
DFN-10 |
Serial Interface |
Part Number |
Output Voltage Range (V) |
Output Current Range |
Interface |
Packages |
A3972 |
15 to 50 |
1.5 A |
Serial |
DIP-24 |
A3992 |
15 to 50 |
1.5 A |
Serial |
DIP-24, eTSSOP-24 |
A3998 |
9 to 50 |
1.5 A |
Serial |
QFN-32 |
A3985 |
12 to 50 |
<10 A Typical (MOSFET gate driver IC) |
Serial |
TSSOP-38 |
A3981K |
7 to 50 |
1.4 A |
SPI/Parallel (Translator) |
eTSSOP-28 |
A4979 |
7 to 50 |
1.5 A |
SPI/Parallel (Translator) |
eTSSOP-28 |
A4980K |
3.3 to 50 |
1.4 A |
SPI/Parallel (Translator) |
eTSSOP-28 |
A4992K |
7 to 50 |
1.4 A |
Parallel/SPI (Translator) |
eTSSOP-20 |
Note: "K" suffix denotes automotive grade product (AEC-Q100 qualified)
The following devices are pre-End-of-Life: A3986