ADM1172 2.7 V to 16.5 V Hot Swap Controller with Power-Good Comparator

The ADM1172 is a Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. This is achieved using a pass FET with a current control loop that monitors the input current using a sense resistor. An internal charge pump is used to enhance the gate of the external high side N-channel FET. When an over current condition is detected the gate voltage of the FET is reduced to limit the current flowing through the sense resistor. The ADM1172 operates with a supply voltage ranging from 2.7V to 16.5V. During an overcurrent condition the timer cap determines the amount of time the FET will remain in this condition. The ON (ON/CLR) pin is the enable input for the device and also acts as a latched fault reset for the ADM1172-2 model. The ADM1172 also features a power fail comparator. The voltage on the PFI pin is compared with an internal 0.6V reference and the output of this comparator is presented on the PFO pin.

This device is available in two options: the ADM1172-1 will automatic retry for over-current fault and the ADM1172-2 will latch-off for an over-current fault. The ADM1172 is packaged in an 8-lead TSOT package.