Let's pretend we have a standard 4 MOSFET H-bridge that controls a 12V brushed DC motor. When driving the motor forward, we can keep SW4 on continuously and pulse SW1 on and off (see below image). If I understand correctly, in this case during the off-state, the motor will be essentially open-circuited, and no current will flow through it, in what is called "coasting".
However I stumbled upon a motor driver IC (DRV8812) which in one particular mode of operation (EN/PH mode, see below image), forces you to switch between "forward" and "brake" when using PWM (assuming the PWM frequency is faster than the
tSLEEP timeout of 1ms or so). When
EN goes low (the datasheet says to connect the PWM to
EN), it turns both SW2 and SW4 on, causing the motor to "brake". A first glance this seems like a bad idea, why would you want to brake and waste more energy than you need to when driving the motor (and slow it down). Is there a benefit to this style of control?