SLVSD14A June 2017 – June 2020 DRV10983-Q1
When the DRV10983-Q1 device transitions from driving the motor into a high-impedance state, the inductive current in the motor windings continues to flow and the energy returns to the power supply through the intrinsic body diodes in the FET output stage (see Figure 40).
To prevent the inductive energy from being returned to the power supply, the DRV10983-Q1 system transitions from driving to a high-impedance state by first turning OFF the active high-side drivers, and turning ON all low-side drivers. The DRV10983-Q1 device monitors phase current after entering the BRAKE state and transitions into the high-impedance state when the amplitude of the phase current is less than BrkCurThrSel for a fixed period of time (BrkDoneThr[2:0])(see Figure 41).
In this example, current is applied to the motor through the high-side driver on phase U (S1) and returned through the low-side driver on phase W (S6). The high-side driver on phase U is turned off and after a period of time (to allow the inductive energy in the resulting LR circuit to decay) the low-side driver on phase W is turned off. If BrkDoneThr[2:0] = 000, no brake will be applied and the device will not protect from inductive energy even with the inductive AVS feature enabled.