4.8 Overcurrent Protection

To protect the motor, the power stage, and the power supply, an overcurrent protection method is needed. This is accomplished with the help of a current shunt which gives out an analog signal with a DC offset of V_DD/2, so that the voltage can swing in both directions. Thus, at a value of V_DD/2 the system draws zero amps.

For faster response time, two internal Analog Comparators in Window mode are used to detect the overcurrent.

The upper and lower limits of the window are generated using two DACs, one for each comparator. An interrupt generated by this current window will force the system into a Fault state.