LP5907-Q1: LP5907-Q1 related issues

Q1. Thermal shutdown disables the output when the junction temperature rises to approximately 160°C which allows the device to cool. When the junction temperature cools to approximately 145°C, the output circuitry enables. Based on power dissipation, thermal resistance, and ambient temperature, the thermal protection circuit may cycle on (disable device) and off (recovery).

Q2. Short-circuit current (ISC) for the LP5907-Q1 is equivalent to current limit which is shown on the DS. In case of a short circuit condition, the device internally limits the current and does not turn off/ is not disabled thus requiring no reset.

For both cases, the mechanism works based on current sensing through the pass FET. The pass element consists of multiple FETs in parallel for current sharing. One of the FETs acts as a sensing element and the sensed current is compared internally via a Schmitt trigger- comparator network to the reference value to initiate disable (in case of thermal shutdown) or current limiting (for short circuit)

Thermal protection kicks in at junction temperature of160 °C. The procedure to design for operating conditions to keep Tj below this value is explained in section 8.2.2.1 of the DS. The current limit range is also shown on the DS in section 6.5 (250 - 500 mA)