SLOA312 December   2021 DRV8412 , DRV8424 , DRV8426 , DRV8428 , DRV8434 , DRV8436 , DRV8803 , DRV8804 , DRV8805 , DRV8806 , DRV8844 , DRV8847 , DRV8932 , DRV8935 , DRV8955

PRODUCTION DATA  

  1.   Trademarks
  2. 1Introduction
  3. 2Principle of Operation
    1. 2.1 Unipolar Stepper Motors
    2. 2.2 Bipolar Stepper Motors
  4. 3How to Drive Unipolar Stepper Motors with DRV8xxx Drivers
    1. 3.1 Driving Unipolar Motor with Four-channel Low-side Driver
    2. 3.2 Driving a Unipolar Motor with a Bipolar Driver
    3. 3.3 Driving Unipolar Motor with Four-channel Half-Bridge Driver
      1. 3.3.1 Driving in Full-step Mode
        1. 3.3.1.1 Full-step Mode with One Phase ON
        2. 3.3.1.2 Two Phases ON
      2. 3.3.2 Driving in Half-step Mode
      3. 3.3.3 Example Pseudocode
        1. 3.3.3.1 Code for Full-step with One Phase ON
        2. 3.3.3.2 Code for Full-step with Two Phase ON
        3. 3.3.3.3 Code for Half-step
  5. 4References

3.3.1.1 Full-step Mode with One Phase ON

In this mode of operation, only one low-side MOSFET is turned on at a time, therefore the driving method is the simplest. The truth table and timing diagram for this mode of operation are shown in Table 3-4.

Figure 3-6 and Figure 3-7 show the input and output waveforms when driving a unipolar stepper motor in one phase ON mode with the DRV8935.

Table 3-4 Truth Table and Timing Diagram
INDEX IN1 IN2 IN3 IN4
1 0 1 1 1
2 1 0 1 1
3 1 1 0 1
4 1 1 1 0
GUID-901DDA32-0B83-42DF-9CC7-61F6EB7B0F95-low.png Figure 3-6 Input PWM Signal
GUID-E3B8EEB7-84CA-4904-9B75-2350F0C8D90D-low.png Figure 3-7 Output node waveforms of DRV8935