The device has CAT_FAULT# output on pin 28 which alerts the system to potentially catastrophic power supply faults. The CAT_FAULT# output is an open-drain output and must be pulled up externally through a pullup resistor. The recommended CAT_FAULT# pull-up resistor value is 3.3 kΩ to 10 kΩ while pulling up to 3.3 V voltage source through a 4.99 kΩ resistor is commonly used. The CAT_FAULT# function is activated after VCC/VDRV pin voltage rises above VCC UVLO rising threshold (3.2V typical) regardless of by EN pin logic level.

Fault conditions which assert the CAT_FAULT# pin include:

• Over-voltage fault detected by fixed VOUT OVP
• Over-voltage fault detected by tracking VOUT OVP
• Under-voltage fault detected by tracking VOUT UVP, including the an UV fault caused by overcurrent event
• Over-temperature fault (based on the threshold set through I2C in (4Fh) OT_FAULT_LIMIT register)
• Powerstage OT or VDRV_UV faults (Either fault asserts PS_FLT status bit in (80h) STATUS_MFR register)

Once asserted low by a fault event CAT_FAULT# pin latches low until a reset of PVIN or an EN toggle.