SLVSDF3F MARCH 2017 – JANUARY 2019 TPSM846C23
An internal temperature sensor based off the bandgap reference protects the TPSM846C23 device from thermal runaway. The internal thermal shutdown threshold, TSD, is fixed at 145°C (typical), which is different from the user programmable OT_FAULT_LIMIT. When the device senses a temperature above TSD, an otf_bg bit in the STATUS_MFR_SPECIFIC command is flagged, and power conversion stops until the sensed junction temperature decreases by the amount of the thermal shutdown hysteresis, THYST (20°C typical). The SMBALERT signal is triggered if the signal is not masked.
The device response to an OT_FAULT_LIMIT event can be set to Latch-off, Restart and Ignore in OT_FAULT_RESPONSE. The default response to an over temperature fault is to shut down and then restart. Fixed band gap-detected overtemperature (OT) faults are never ignored. The band gap OT faults always respond in a shutdown and attempted restart once the device cools. Table 7 summarizes the fault-response scheme.