The Maxim Integrated MAX5921AESA+ is a single-channel hot swap controller designed for -48V power systems, the standard voltage in telecom central offices, base stations, and -48V battery-backed industrial equipment. It manages the inrush current and protects against overcurrent, overvoltage, and undervoltage faults — all without an internal pass FET, so the designer selects the external MOSFET that matches the load current and thermal budget.
Programmable protection and fault handling
The MAX5921AESA+ integrates programmable circuit breaker, current limit, overvoltage protection (OVP), and undervoltage lockout (UVLO), giving the designer control over the turn-on threshold and the fault-trip level. On a fault, the auto-retry feature cycles the output — useful for clearing transient overloads without a manual reset. The thermal limit shuts down the controller if the die temperature exceeds safe operating area, protecting both the IC and the external MOSFET.
Housed in an 8-pin SOIC (0.154" body width, 3.90 mm width), the MAX5921AESA+ is a surface-mount part that reflows on a standard lead-free profile. The small footprint keeps board area low, but the external MOSFET and sense resistor will dominate the hot-swap circuit's real estate.
It is ROHS3 compliant.