DRV8876: Phase/Enable and PWM Modes

Hi Ponlakshmi,

PH/EN is a speed and direction type interface (look at table 3 on the datasheet). It is a simpler interface, compared to PWM, since at most only EN can be connected to a timer pin on the MCU to generate a PWM signal with adjustable duty cycle to control the speed of the motor. However, if you plan to drive the motor at 100% duty cycle and are not concerned about speed control, EN can be set high and PH can be set to low or high depending on the desired direction which can save you a timer pin on the MCU. A drawback of PH/EN is that the outputs cannot be placed in High-Z state unless nSLEEP=0 (device is placed in sleep mode).

PWM provides a more flexible way to drive the motor. the FETs can be placed in high-Z state without placing the device to sleep (look at table 4 on the datasheet). The motor speed and direction can be controlled in a similar fashion to PH/EN where only one signal can be toggling and the other be fixed to high or low depending on desired direction. Another way to control speed and direction with PWM interface is by toggling both signals (IN1 and IN2). The duty cycle of IN1 and IN2 will determine the speed and direction of the motor.