ZHCSAM1F December 2012 – December 2017 TPS7A66-Q1 , TPS7A69-Q1
PRODUCTION DATA.
These devices incorporate a thermal shutdown (TSD) circuit as a protection from overheating. For continuous normal operation, the junction temperature should not exceed the TSD trip point. If the junction temperature exceeds the TSD trip point, the output turns off. When the junction temperature falls below the TSD trip point, the output turns on again.
Thermal protection disables the output when the junction temperature rises to approximately 170°C, allowing the device to cool. Cooling of the junction temperature to approximately 150°C enables the output circuitry. Depending on power dissipation, thermal resistance, and ambient temperature, the thermal protection circuit may cycle on and off. This cycling limits the dissipation of the regulator, protecting it from damage as a result of overheating.
The purpose of the design of the internal protection circuitry of the TPS7A66-Q1, TPS7A69-Q1 is for protection against overload conditions, not as a replacement for proper heat-sinking. Continuously running the TPS7A66-Q1 or TPS7A69-Q1 into thermal shutdown degrades device reliability.