DRV8874：DRV8874 toff time

Hi Jung,

Do you want to ask if the DRV8874 is operating in PWM mode will need t-off time?

You do not need Toff time. Toff is a feature that can be used to limit the current in the load when the inputs are set to 100% duty cycle.

Please refer to section 7.3.3.2.1 Fixed Off-Time Current Chopping and Figure 32..

Once the current reaches the level set by Itrip, the device will regulate the current. This feature is typically used during motor startup and stall conditions.

When need t-off time , is the minimum time for closing time 20us?

There is no minimum time. The outputs will be reset to normal operation at the beginning of the next PWM input cycle. Figure 31 is an example of this.

Toff begins approximately 4us after the rising edge of EN. Toff would typically be active for 25us. In this example a new PWM cycle begins 16us after Toff begins.

This resets Toff and begins a new cycle at the outputs.