7.4.1.2 Thermal Protection

Thermal protection disables the output when the junction temperature rises to approximately 160°C, allowing

the device to cool. When the junction temperature cools to approximately 140°C, the output circuitry is again

enabled. Depending on power dissipation, thermal resistance, and ambient temperature, the thermal protection

circuit can cycle on and off. This limits the dissipation of the regulator, protecting the device from damage due to

overheating.

Any tendency to activate the thermal protection circuit indicates excessive power dissipation or an inadequate

heat sink. For reliable operation, junction temperature must be limited to 125°C maximum. To estimate the

margin of safety in a complete design (including heat sink), increase the ambient temperature until the thermal

protection is triggered; use worst-case loads and signal conditions. For good reliability, thermal protection must

trigger at least 35°C above the maximum expected ambient condition of your application. This produces a

worst-case junction temperature of 125°C at the highest expected ambient temperature and worst-case load.

The internal protection circuitry of the TPS736 has been designed to protect against overload conditions. This

circuitry is not intended to replace proper heat sinking. Continuously running the TPS736 into thermal shutdown

degrades device reliability.

7.4.2 Layout Examples

NR/FB

EN

1

2

3

4

8

7

6

5

GND PLANE

GND PLANE

CIN

COUT

C

NR

N/C

N/C

N/C

VOUT

VIN

TPS736xxDRB

Figure 7-11. Fixed Output Voltage Option Layout (DRB Package)

www.ti.com

TPS736

SBVS038X – SEPTEMBER 2003 – REVISED MAY 2025

Copyright © 2025 Texas Instruments Incorporated

Submit Document Feedback

25

Product Folder Links: TPS736