Hi Bruce,
Thank you for your question.
The DRV8701E is the PH/EN control variant of the DRV8701 smart gate driver. In PH/EN control mode the PH pin phase controls the direction of the bridge and the EN pin enable enables and disables the bridge. The EN pin can accept a PWM input up to 100 kHz frequency and variable duty cycle between 0 and 100 %. When the duty cycle is varied the motor speed will vary. Typically a 20 kHz PWM is used in most applications for the speed control PWM. When the EN is logic 1, the motor will run with full speed and when EN is logic 0 the motor will stop with low-side FETs conducting recirculation or brake. See below control table from the datasheet.
In addition to this, the DRV8701 also features on-chip current regulation, used for limiting the startup inrush current or stall current of the motor. See below info from the datasheet. Current regulation is done with the help of on-chip current sense amplifier - see second snippet. This feature can be disabled if it is not needed.
Regards, Murugavel
