Ideal Diode and Hot Swap Controller

The LTC4229 offers ideal diode and Hot Swap™ functions for a power rail by controlling two external N-channel MOSFETs. The MOSFET acting as an ideal diode replaces a high power Schottky diode and the associated heat sink, saving power and board area. The Hot Swap MOSFET control allows a board to be safely inserted and removed from a live backplane by limiting inrush current. The supply output is also protected against short-circuit faults with a fast acting foldback current limit and electronic circuit breaker.

The LTC4229 regulates the forward voltage drop across the external MOSFET to ensure smooth current transfer in diode-OR applications. The ideal diode turns on quickly to reduce the load voltage droop during supply switchover. If the input supply fails or is shorted, a fast turn-off minimizes reverse-current transients.

The LTC4229 provides adjustable start-up delay, undervoltage and overvoltage protection, and reports fault and power good status for the supply. It can be configured for latch off or automatic retry after a fault.

Applications

* Redundant Power Supplies

* Supply Holdup

* High Availability Systems and Servers

* Telecom and Network Infrastructure

* Power Prioritizer

* Ideal Diode and Inrush Current Control for Redundant Supplies

* Low Loss Replacement for Power Schottky Diode

* Protects Output Voltage from Input Brownouts

* Allows Safe Hot Swapping from a Live Backplane

* 2.9V to 18V Operating Range

* Controls Back-to-Back N-Channel MOSFETs

* Limits Peak Fault Current in ≤1μs

* Adjustable Current Limit with Foldback

* Adjustable Start-Up and Current Limit Fault Delay

* 0.5μs Ideal Diode Turn-On and Turn-Off Time

* Undervoltage and Overvoltage Protection

* Status, Fault and Power Good Outputs

* Pin Selectable Latch Off or Automatic Retry After Fault

* 24-Lead 4mm × 5mm QFN and SSOP Packages