ZHCSRU8 February 2024
PRODUCTION DATA
The voltage on VOSNS pin is monitored to provide output voltage overvoltage (OV) and undervoltage (UV) protection. When VOSNS voltage is higher than OV fault threshold, OV fault is declared and the low-side FET is turned on to discharge the output voltage and eliminate the OV condition. The low-side FET remains on until the VOSNS voltage is discharged to 200mV divide by the internal feedback divider as programmed by (29h) VOUT_SCALE_LOOP. After the output voltage is discharged, the output is disabled and the converter times out and restarts according to the (41h) VOUT_OV_FAULT_RESPONSE PMBus command. When VOSNS voltage is lower than UV fault threshold, UV fault is declared. After an initial delay programmed by the (45h) VOUT_UV_FAULT_RESPONSE PMBus command, the output is disabled and the converter times out and restarts according to the (45h) VOUT_UV_FAULT_RESPONSE PMBus command.
The output UV/OV fault thresholds and fault response are set through PMBUS. The UV/OV fault response can be set to shutdown, restart, or continue operating without interruption.