Dual-channel hot swap and OR controller for 2.9V to 18V rails
The Analog Devices LTC4228IUFD-1#PBF is a dual-channel Hot Swap Controller and OR Controller in a single 28-QFN package. It manages two independent supply rails between 2.9V and 18V, with programmable current limit, fault timeout, and slew rate to control inrush current during board insertion. The latched-fault and undervoltage lockout (UVLO) features protect against overcurrent and brownout conditions. This part is aimed at general-purpose hot-swap and redundant-power applications where two rails need sequenced or OR-ed control — think RAID backplanes, base-station line cards, or any system with dual redundant feeds.
Two channels, no internal switches — plan for external MOSFETs
The LTC4228IUFD-1#PBF has two independent channels but no internal switches. Each channel drives an external N-channel MOSFET to control the power path. That means the BOM includes two FETs plus the associated gate-drive and sense-resistor network. The trade-off is flexibility: you size the FETs for your load current, not a fixed internal limit. The 2.5 mA supply current is the controller's own draw; the pass-FETs add their own gate charge overhead during switching.
Package and footprint — 28-QFN with exposed pad
The supplier device package is 28-QFN measuring 4x5 mm. The exposed pad must be soldered to a thermal land on the PCB for heat dissipation.
Temperature grade and environment
Rated for -40°C to 85°C operating temperature, this is an industrial-temperature part. It fits outdoor telecom cabinets, factory-floor equipment, and any environment where the board sees seasonal temperature swings but not engine-bay heat.
Lifecycle and sourcing
The LTC4228IUFD-1#PBF is listed as Active and ROHS3 compliant.