What is a thermal shutdown circuit?

LDO Linear RegulatorsDC/DC Switching RegulatorsSwitch ICsLED Driver Controller ICsProtection

The Thermal Shutdown Circuit detects overheating of the LDO regulator if the output pin (VOUT) is shorted to the ground pin (GND) and stops the LDO regulator operation to protect it from damage.

For example, the Thermal Shutdown Circuit stops LDO regulator operation if the junction temperature of the R1150 Series becomes higher than 150°C. Additionally, if the junction temperature after the LDO regulator being stopped decreases to a level below 125°C, it restarts LDO regulator operation. (The temperature is different according to the product).
As a result the operation of the Thermal Shutdown Circuit causes the LDO regulator repeatedly to turn OFF and ON till the causes of overheating are removed. As a consequence a pulse shaped output voltage occurs. Please prevent this situation.

In the datasheet it is shown as a thermal shutdown detection temperature and a thermal shutdown release temperature.

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  R1150 Block Diagram

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  R1150 (VOUT=5V)
  Output Voltage vs. Junction Temperature

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  R1150 Temperature and Regulator

The conditions under which this protection circuit operates are not guaranteed because it exceeds the absolute maximum rating. It is just an auxiliary function. Design this protection circuit so that it does not work.