Stepper Motor Driver

The stepper driver is an electric device that converts electronic signals into mechanical motion. It is a device that produces a quantitative angular displacement of the stepper motor. It can convert control signals into rotational steps with high precision and controllability.

Stepper drivers are widely used in various fields such as CNC machine tools, printing machines, weaving machines, packaging machines, textile machines, medical equipment, etc.

(Motor Driver)

(Motor Structure)

Components

The stepper motor control system consists of three parts: stepper motor controller, stepper motor driver, and stepper motor. The stepper motor controller is the command center, which sends signal pulses to the stepper motor driver, and the stepper motor driver converts the received signal pulses into electrical pulses to drive the stepper motor to rotate. For each signal pulse sent by the controller, the stepper motor rotates an angle. Its rotation is in fixed steps. The controller can control the rotation angle of the stepper motor by controlling the number of pulses, thereby achieving precise positioning. The rotation speed of the stepper motor can be precisely controlled by controlling the pulse frequency.

Principle of Stepper Motor Driver

It is powered by a unipolar DC power supply. As long as the various phase windings of the stepper motor are energized in the appropriate sequence, the stepper motor can step and rotate.

However, the stepper motor cannot be directly connected to the mains AC or DC power supply, and must be used with a dedicated stepper motor driver, which consists of a pulse generation control unit, a power drive unit, a protection unit, etc. The drive unit is directly coupled to the stepper motor and can also be understood as the power interface of the stepper motor microcontroller. The MCU acts as the brain controlling the motor, sending the motor's step angle time, rotation direction, and number of repetitions to the discrete devices, and the discrete devices amplify the voltage and current and send it to the motor to drive it to rotate.

The core circuit of the brushed motor driver H-bridge, together with some necessary peripheral circuits, forms the driver of the DC brushed motor. Integrated circuit form H-bridges are generally used for medium and small powers. The discrete component form of the H-bridge is usually used for high power or ultra-high power requirements, mainly composed of MOSFET or IGBT transistors. The pins of the MCU cannot directly drive components such as MOS transistors, and a dedicated MOS transistor driver chip needs to be added. The DC brushed motor driver chip L298N integrates two H-bridges internally. The L298N chip can drive motors from 4.5V to 46V, with a current output of less than 2A and a peak current output of 3A. In actual applications, the control of forward and reverse cannot be achieved by switching the power supply lines, and an H-bridge circuit can be used to drive the motor.

From the above roles, it can be seen that the stepper motor driver is a very important product. Therefore, choosing the right MOSFET is essential to ensure the quality of the product.

VBsemi VB has a rich range of MOSFET products that can better match various high and low voltage requirements of stepper motor driver series products. The following is a reference list of models and corresponding parameters:

(MOS models used in stepper motor drivers)