SLLSFT3 November 2025 MC121-Q1
ADVANCE INFORMATION
When the VM voltage exceeds the VOVP rising threshold, all FETs are in Hi-Z and the FG/RD pin indicates the locked rotor fault according to Table 6-4. When the VM voltage drops below the VOVP falling threshold, normal device operation resumes. The OVP threshold is set by OVP_SEL and can be disabled by setting OVP_EN to 0x0. Overvoltage protection has a fixed deglitch time of 80µs to eliminate spurious OVP triggers. To avoid false OVP triggers due to transient VM spikes during normal motor operation, the overvoltage protection is disabled during the rise and fall intervals of soft commutation. In addition, OVP is always disabled during the demagnetization interval. Also, an optional (enabled by setting OVP_BLANK_EN to 0x1) blanking time set by OVP_BLANK_SEL (1ms or 4ms) is provided during the peak duty cycle interval to improve OVP detection robustness. Figure 6-30 shows the OVP detection operation in different intervals of soft commutation. In square commutation, there are no rise/fall intervals and the blanking time, when enabled, is applied from the commutation instant.