ZHCSH28C September 2017 – May 2025 TPA3221
PRODUCTION DATA
The PPSC detection system protects the device from permanent damage in the case that a power output pin (OUT_X) is shorted to GND_X or PVDD_X. For comparison, the OC protection system detects an overcurrent after the demodulation filter where PPSC detects shorts directly at the pin before the filter. PPSC detection is performed at startup after RESET is pulled high. When PPSC detection is activated by a short on the output, all half-bridges are kept in a Hi-Z state until the short is removed; the device then continues the startup sequence and starts switching. The detection is controlled globally by a two step sequence. The first step ensures that there are no shorts from OUT_X to GND_X, the second step tests that there are no shorts from OUT_X to PVDD_X. The total duration of this process is roughly proportional to the capacitance of the output LC filter. The typical duration is < 15 ms/μF. While the PPSC detection is in progress, FAULT is kept low. If no shorts are present the PPSC detection passes, and FAULT is released. A device reset will start a new PPSC detection. PPSC detection is enabled in both BTL and PBTL output configurations. To make sure not to trip the PPSC detection system it is recommended not to insert a resistive load to GND_X or PVDD_X.