SLVS736C February 2008 – October 2023 TPS2550 , TPS2551
PRODUCTION DATA
The TPS2550/51 protects itself with two independent thermal sensing circuits that monitor the operating temperature of the power-switch and disables operation if the temperature exceeds recommended operating conditions. The device operates in constant-current mode during an overcurrent conditions, which increases the voltage drop across power-switch. The power dissipation in the package is proportional to the voltage drop across the power-switch, so the junction temperature rises during an overcurrent condition. The first thermal sensor turns off the power-switch when the die temperature exceeds 135°C and the part is in current limit. The second thermal sensor turns off the power-switch when the die temperature exceeds 155°C regardless of whether the power-switch is in current limit. Hysteresis is built into both thermal sensors, and the switch turns on after the device has cooled approximately 15°C. The switch continues to cycle off and on until the fault is removed. The open-drain false reporting output FAULT is asserted (active low) immediately during an overtemperature shutdown condition.