"Exposing a Flaw: Shoot-Through" describes the serious problem with that circuit, especially when pulsed
Above is an improved version of the circuit, which is now PWM compatible. PWM, coast mode, and the capability to avoid shoot-through are provided by adding a fifth MOSFET (labeled Q5) to the source/ground connections of Q1 and Q3.
By default at power-up, the circuit is in coast mode.
To brake, set IN A to 0 V, IN B to 0 V, and Q5 to 5 V.
To spin clockwise, set IN A to 5 V, IN B to 0 V, and Q5 to 5 V.
To spin counterclockwise, set IN A to 0 V, IN B to 5 V, and Q5 to 5 V.
At any time you can return to coast by applying 0 V to Q5.
Or, you can apply pulses of 0 V/5 V/0 V/5 V (and so on) to control the speed. The more time spent at 5 V, the faster the motor will spin.
Whenever you change modes, if you set Q5 to 0 V before making changes to IN A and IN B (and then set Q5 back to 5 V or pulsing) there will be no shoot-through.
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