7.1 Overview

The inline protection functionality of the LM5069 is designed to control the in-rush current to the load upon insertion of a circuit card into a live backplane or other hot power source, thereby limiting the voltage sag on the backplane's supply voltage and the dV/dt of the voltage applied to the load. Effects on other circuits in the system are minimized, preventing possible unintended resets. A controlled shutdown when the circuit card is removed can also be implemented using the LM5069.

In addition to a programmable current limit, the LM5069 monitors and limits the maximum power dissipation in the series pass device to maintain operation within the device Safe Operating Area (SOA). Either current limiting or power limiting for an extended period of time results in the shutdown of the series pass device. In this event, the LM5069-1 latches off while the LM5069-2 retries an infinite number of times to recover after the fault is removed. The circuit breaker function quickly switches off the series pass device upon detection of a severe overcurrent condition. Programmable undervoltage lockout (UVLO) and overvoltage lockout (OVLO) circuits shut down the LM5069 when the system input voltage is outside the desired operating range.