STK984-090A-E Short-circuit Protection Circuit The Short-circuit Protection Circuit monitors the drain voltage of the high side MOSFET to detect short circuits. This circuit detects a short circuit when a short circuit current flows for longer than tspoff (typically 3μs). The outputs are switched to the OFF state and the DIAG1 signal is switched HIGH. The IPM is then latched in the short-circuit protection state. This state can be released by setting the RESET input LOW and then HIGH again. Figure 11: Timing Diagram Short-circuit Condition Over-current Protection Circuit The Over-current Protection Circuit monitors the drain voltage of the low-side MOSFETs to detect over currents. This circuit detects a short circuit when a short circuit current flows for longer than tocoff (typically 4.3μs). When a short circuit is detected, the outputs are switched off and the short circuit condition is flagged by switching on DIAG1. The over-current protection state is held for time tINT (typically 1ms) then released. It is not latched like the short-circuit current protection mode. Figure 12: Timing Diagram for Over-current Protection www.onsemi.com 12