Summary of 3A Unipolar Stepper Motor Driver
This article describes a compact Unipolar stepper motor driver based on the Sanken SLA7078MPR IC, capable of handling up to 3 Amps and supporting micro-stepping up to 1/16. It features on-board jumpers for step configuration and a potentiometer for current adjustment. The driver supports both Stand-Alone operation using Pulse and Direction signals, and Microcontroller Interface modes with Auto Half Current functionality via SYNC and Ref pins for CNC applications like robotics and engraving.
Parts used in the Unipolar Stepper Motor Driver:
- SLA7078MPR IC from Sanken
- On-board Jumpers
- Preset Potentiometer
- CLOCK pin input interface
- SYNC pin
- Ref/Sleep1 pin
This tiny Unipolar stepper motor driver has been designed around SLA7078MPR IC from Sanken, It is unipolar stepper Motor driver can handle current up to 3 Amps, micro-stepping up to 1/16 steps. On-board Jumpers to set the Micro-stepping, Preset (Potentiometer) to set the current.
The SLA7070MPR series motor driver ICs features unipolar drivers. The clock-in type input interface allows simplified control logic, and options for built-in sense current detection and load circuit short or open protection (patent pending) provide lower loss, and lower thermal resistance.
The built-in excitation distribution circuit (sequencer) allows motor control using only the CLOCK signal for simple operations (rotate/stop), with motor speed control by frequency input into CLOCK pin. This eliminates logic signal lines required for conventional phase-input methods, and reduces demand on heavily-used CPUs.
Unipolar stepper board is high efficient stepper driver for Unipolar stepper motor been design for various application like robotics, control routers, lathes, mills, PCB drillers and engravers.
This board has been designed to be used in two ways, Stand Alone and Microcontroller Interface or Auto Half Current.
Stand Alone
Just to Rotate Motor normally bellow inputs required:
- Pulse (Step Pulse In) Frequency
- Direction
- 5V DC
- GND
- SYNC and REF doesn’t Required for this operation.
Microcontroller Interface or Auto Half Current
For Micro-Controller Interface or Auto Half Current (while Motor is in Hold-State):
Usually In Motion control and CNC application stepper motor driver required auto Half Current function specially while motor is not moving and it’s in hold-state. For this operation SYNC and Ref required input signal.
- SYNC input is for chopping synchronous function to protect from abnormal noises that may occasionally occur during the Motor Hold-State. This function can be operated by setting SYNC pin at high level.
- Ref/Sleep1 – To set the half current in Motor Hold State this pin required appropriate voltage input. Also this pin can be use to driver in to sleep mode by just applying High level to this pin.
For more detail: 3A Unipolar Stepper Motor Driver
- What is the maximum current this driver can handle?
The driver can handle current up to 3 Amps. - How do I set the micro-stepping resolution?
You use the on-board Jumpers to set the micro-stepping level. - Can I control motor speed without a CPU?
Yes, by inputting frequency into the CLOCK pin for simple operations. - What pins are required for Stand Alone mode?
Pulse, Direction, 5V DC, and GND are required; SYNC and REF are not needed. - How does the Auto Half Current function work?
It requires SYNC and Ref input signals to reduce current while the motor is in hold-state. - What is the purpose of the SYNC pin?
SYNC protects against abnormal noises during the Motor Hold-State when set at high level. - How can I put the driver into sleep mode?
Apply a High level to the Ref/Sleep1 pin to drive the driver into sleep mode. - Does the IC offer protection features?
Yes, it includes built-in sense current detection and load circuit short or open protection.
