The Cool-Switch® PI2161 is a complete full-function Load Disconnect Switch solution for medium voltage applications with a high-speed electronic circuit breaker and a very low on-state resistance MOSFET. It is designed to protect an input power bus from output load fault conditions. The PI2161 Cool-Switch solution is offered in an extremely small, thermally enhanced 7 mm x 8 mm LGA package. The PI2161 enables an extremely low power loss solution with fast dynamic response to an over current fault or EN high conditions. The PI2161 senses a small portion of the total MOSFET current and has a low voltage threshold allowing the use of low power sense resistors.

The switch is closed when the EN input is low and is open when EN is high. Once enabled, the PI2161 monitors the MOSFET current through a sense resistor. If an overcurrent level is sensed, the switch is quickly latched off to prevent the power source from being overloaded. Bringing the EN pin high will reset the overcurrent latch allowing retry. The PI2161 has an internal 10 kO bias resistor connected between the Drain (D) and VC to eliminate need for external resistor in a 44 V bus application (41 V to 48 V).