Wide-range hot swap controller in SOT-23-6
The MAX5902ACEUT is a single-channel hot swap controller from the Simple Swapper™ series, designed to manage inrush current and protect against overcurrent and fault conditions on a live backplane or power rail. Its 9V to 72V supply range covers common telecom and industrial bus voltages — 12V, 24V, 48V, and 60V — without needing a separate bias rail. The controller draws only 1 mA from the supply, keeping the quiescent overhead negligible in a system that may have multiple hot-swap slots.
Programmable protection and fault handling
Programmable features include an adjustable current limit, circuit breaker threshold, slew rate for the external pass FET, fault timeout, auto-retry, thermal limit, and undervoltage lockout (UVLO). The auto-retry and fault timeout work together to clear transient overcurrent events without latching off the load, while a persistent fault cycles the power until the condition clears. Because the MAX5902ACEUT has no internal switch, an external N-channel MOSFET carries the load current — the controller drives the gate with a controlled slew rate to limit the inrush capacitor charging current.
Active lifecycle and compliance note
Note that this part is listed as RoHS non-compliant, which may affect its use in regions with strict RoHS enforcement or in designs that require full RoHS conformance.