The ADM1172 is a hot swap controller that safely enables a printed circuit board to be removed and inserted to a live backplane. This is achieved using an external N-channel power MOSFET with a current control loop that monitors the load current through a sense resistor. An internal charge pump is used to enhance the gate of the 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. During an overcurrent condition, the TIMER pin capacitor determines the amount of time the FET remains at a current limiting mode of operation until it is shut down. The ON (ON- Allows protected board removal and installation.
The ADM1172 is a hot‑swap controller that enables safe insertion and removal of printed‑circuit boards on a live backplane. It uses an external N‑channel MOSFET and a sense resistor to monitor load current, and an internal charge pump to drive the MOSFET gate. When an over‑current condition is detected, the device reduces the gate voltage to limit current and can enter a circuit‑breaker mode.
Key features include a power‑fail comparator with a 0.6 V reference, adjustable analog current limit via an external sense resistor, automatic retry or latch‑off during fault, and operation over a wide supply range (2.7 V‑16.5 V). The device is supplied in an 8‑lead TSOT package and is intended for hot‑swap board insertion in line cards, RAID systems, industrial high‑side switches, and electronic circuit breakers.
| Operating Voltage Range | 2.7 V to 16.5 V |
|---|---|
| Supply Current (typical) | 0.8 mA |
| Undervoltage Lockout (UVLO) Threshold | 2.525 V to 2.65 V |
| ON (ON‑CLR) Pin Threshold | 1.22 V to 1.38 V |
| GATE Pin Drive Voltage | 4.6 V to 10 V |
| TIMER Pin High Threshold | 1.22 V to 1.38 V |
| TIMER Pin Low Threshold | 0.15 V to 0.25 V |
The device operates from 2.7 V up to 16.5 V.
It is supplied in an 8‑lead Thin Small Outline Transistor (TSOT) package.