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The TPS22951 smart-load switch is intended for applications where heavy capacitive loads and short circuits are likely to be encountered. This device incorporates a 1-Ω P-channel MOSFET power switch for power distribution. The switch is controlled by a logic enable (EN) input and an accessory detect (DET) pin. The switch is active when EN is high and DET is low. The switch is disabled if EN is low or DET is high. A low power state is achieved by driving EN low.

When the output load exceeds the current-limit threshold or a short is present, the device limits the output current to a safe level by increasing the on resistance of the power switch. When continuous heavy overloads and short circuits increase the power dissipation in the switch, causing the junction temperature to rise, a thermal-protection circuit shuts off the switch to prevent damage. The device recovers from a thermal shutdown once the device has cooled sufficiently, but the switch remains OFF until EN is toggled. This smart-load switch is designed to set current limit at 600 mA maximum.