Let's start our journey into stepper motor operation!

A tour of stepper motor operation

Zhishi Classroom has introduced the application, characteristics and working principle of stepper motors. Now you should be eager to try to make your stepper motor work, right? Don't worry, before driving the stepper motor, let's first learn how to drive the stepper motor and choose the appropriate stepper motor driver IC, so that your first stepper motor operation journey will be more wonderful.

In the previous article, we know that the stepper motor is a motor that can be driven step by step to a specified rotation angle. Its rotation is performed step by step at a fixed angle (called "step angle"). The operation of the stepper motor requires an electronic device to drive it, that is, a stepper motor driver. It converts the pulse signal sent by the control system into the angular displacement of the stepper motor, or it can be said that for every pulse signal sent by the control system, the driver makes the stepper motor rotate one step angle, so the speed of the stepper motor is proportional to the frequency of the pulse signal.

The drive of the stepper motor requires a dedicated motor driver IC to provide the corresponding input control signal. There are usually two types of control signal input, namely clock input type and phase input type, as shown in Figure 1.

Figure 1

The timing diagram of various excitation methods of the clock input type is shown in Figure 2. In the clock input type, the motor is controlled by two types of signals, clock and direction. Therefore, you can easily control the motor speed by the clock speed, the motor rotation amount by the number of clocks, and the motor rotation direction by the rotation direction signal.

Figure 2

The timing diagram of various excitation methods of the phase input type is shown in Figure 3. The driver IC input varies depending on the various excitation methods of the phase input type. In the phase input type, the motor is controlled by the signal generated by the current direction and current ratio of each phase, so it is less likely to cause failure due to noise.

Figure 3

There are many common stepper motor drive methods, mainly constant voltage drive, high and low voltage drive, self-excited constant current chopper drive, current comparison chopper drive and submersible drive. However, when designing a motor, no matter which drive method you choose, you need an excellent stepper motor driver IC. Toshiba provides a rich series of stepper motor driver IC products manufactured using the BiCD process, which can provide high precision and high current capabilities. Toshiba's stepper motor driver IC can provide bipolar and unipolar structures to meet the needs of different system drives. Toshiba's stepper motor driver IC products are shown in Figure 4.

Figure 4

Toshiba, which has been focusing on stepper motor driver IC design for many years, has the following technical advantages:

Advanced Dynamic Mixed Decay (ADMD) Technology:

Toshiba’s original ADMD technology tracks input current more closely than conventional mixed-decay mode, enabling highly efficient motor control at high speeds.

Advanced Current Detection System (ACDS) Technology:

Toshiba’s original ACDS technology enables high-precision constant-current motor drive without the need for external current sampling resistors; the reduction in the number of components also helps reduce board size and bill of materials (BOM) costs.

Active Gain Control (AGC) Technology:

AGC technology automatically adjusts the motor drive current according to the motor's load conditions to reduce excess current, thereby significantly reducing the heat generated by the motor driver IC and motor. This helps reduce the overall heat generation and resulting degradation in the system.

Anomaly Detection Technology:

Built-in abnormality detection circuits such as undervoltage (UVLO), overcurrent (ISD), and overtemperature (TSD) help build highly reliable systems. (Note: Built-in error detection functions vary by product.)

After learning so much about stepper motors, are you already eager to start using your stepper motor for the first time?