JAJSH18A March 2019 – September 2019 TPS7A78
A thermal shutdown protection circuit is included to disable VLDO_OUT and to stop the switched-capacitor stage from switching when the junction temperature TJ of the pass-transistor rises to TSD(SHUTDOWN). Thermal shutdown hysteresis assures that the device resets, resumes normal operation, and that VLDO_OUT turns back on when TJ falls to TSD(RESET). Based on the thermal time constant of the die and the device startup time, the device output can cycle on and off until power dissipation is reduced and the junction temperature remains below TSD(RESET).
For reliable operation, limit the junction temperature to the maximum listed in the Recommended Operating Conditions table. Operating above this maximum temperature causes the device to exceed its operational specifications. Although the internal protection circuitry is designed to protect against thermal overload conditions, this circuitry is not intended to replace proper heat sinking. Continuously running the device into thermal shutdown or above the maximum recommended junction temperature reduces long-term reliability.