I'm looking to use an A3941 but I'm getting bogged down in the data sheet. It seems that any time the PWM is low the h-bridge will be in brake mode. Is this true for high frequency (~3kHz) motor control? The PWM/DIR arrangement is attractive for using arduino but I'm not clear how this will affect motor operation, if at all. Thanks!
That is the normal method but I don't have a good explanation why. Look in the section on "Motor control options" on this page: Pololu High-Power Motor Driver 18v25 CS That explains one reason why this method is used.