Ideal-diode current sharing controller for redundant rails
The LTC4376CDHD#PBF is a current sharing controller from Analog Devices that combines an N-channel MOSFET ideal diode with active load balancing. It regulates the forward voltage drop across the internal switch to share load current equally between two parallel power supplies, while the ideal-diode function blocks reverse current when one supply fails or is shorted. The part targets redundant power supplies, portable battery systems, automotive electronics, and computer systems where a single supply failure must not take down the bus.
4V to 40V input, 7A output — sizing the rail
The supply range from 4V to 40V covers 5V, 12V, 24V, and nominal 36V/48V industrial rails. The 7A continuous output rating per channel sets the power budget for the redundant path — two LTC4376CDHD#PBF units in a 1:1 ratio can share a 14A load between two supplies, with each controller seeing half the current. Quiescent current is 150 µA, low enough for always-on battery-backed rails where the controller must monitor the supply without draining the reserve. The 300 ns turn-off delay means the MOSFET gate pulls down fast when reverse current is detected — the body diode conducts only during that 300 ns window, limiting reverse surge energy into the failed supply.
Package thermal reality — 16-DFN with exposed pad
The 16-WFDFN exposed pad (5x4 mm DFN) is the primary thermal path. Surface-mount assembly with standard reflow profile; no special handling beyond ensuring the exposed-pad solder coverage is void-free per IPC-7093.
This limits the LTC4376CDHD#PBF to controlled environments — server rooms, telecom shelters, lab equipment, office electronics. Not rated for under-hood automotive, outdoor telecom cabinets, or industrial floors where ambient exceeds 70°C.