Alternative Parts


Features and Benefits

  • Low Loss Replacement for ORing Diode in Multiple Sourced Power Supplies
  • External N-Channel MOSFETs for High Current Capability
  • Internal Boost Regulator Supply for MOSFET Gate Drive
  • Wide Input Range: 1.2V to 18V
  • Fast Switching MOSFET Gate Control
  • Input Under and Overvoltage Detection
  • STATUS and FAULT Outputs for Monitoring
  • Internal MOSFET Gate Clamp
  • Available in a 10-pin MSOP

Product Details

The LT4351 creates a near-ideal diode using external single or back-to-back N-channel MOSFETs. This ideal diode function permits low loss ORing of multiple power sources. Power sources can easily be ORed together to increase total system power and reliability with minimal effect on supply voltage or efficiency. Disparate power supplies can be efficiently ORed together.

The IC monitors the input supply with respect to the load and turns on the MOSFET(s) when the input supply is higher. If the MOSFET’s RDS(ON) is sufficiently small, the LT4351 will regulate the voltage across the MOSFET(s) to 15mV. A STATUS pin indicates the MOSFET on state.

An internal boost regulator generates the MOSFET gate drive voltage. Low operating voltage allows for OR’ing of supplies as low as 1.2V.

The LT4351 will disable power passage during undervoltage or overvoltage conditions. These voltages are set by resistive dividers on the UV and OV pins. The undervoltage threshold has user programmable hysteresis. Overvoltage detection is filtered to reduce false triggering.

The LT4351 is available in a 10-pin MSOP.


  • Paralleled Power Supplies
  • Uninterrupted Supplies
  • High Availability Systems
  • N + 1 Redundant Power Supplies

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Tools & Simulations


LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.


Models for the following parts are available in LTspice:


Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

PCN-PDN Information

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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

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