Hot swap controller with a 9V–80V input window
The MAX5947BESA+ is a single-channel hot swap controller from Analog Devices, designed to manage inrush current and protect downstream circuitry during board insertion in a live backplane. It accepts a 9V to 80V supply range, drawing 1.4 mA quiescent, and integrates programmable overvoltage (OVP), undervoltage lockout (UVLO), current limit, and fault timeout — all set with external resistors and a capacitor. The 80V upper limit suits it for 48V telecom racks and industrial 24V systems where transients can spike well above the nominal rail. No internal switch means the external N-channel pass FET handles the load current — the controller drives the gate and monitors the sense resistor voltage.
Programmable protection and auto-retry
Four programmable thresholds — UVLO, OVP, current limit, and fault timeout — let you tailor the turn-on and shutdown behaviour to the specific supply impedance and load capacitance. The auto-retry feature cycles the gate after a fault clears, eliminating the need for a manual reset in remote or unattended gear. Thermal limit protection shuts down the controller if the die temperature exceeds the safe operating area, providing a secondary safeguard beyond the current-limit loop.