LTC4225-1/LTC4225-2 - Dual Ideal Diode and Hot Swap Controller


  • Power Path and Inrush Current Control for Redundant Supplies
  • Low Loss Replacement for Power Schottky Diodes
  • Allows Safe Hot Swapping from a Live Backplane
  • 2.9V to 18V Operating Range
  • Controls N-Channel MOSFETs
  • Limits Peak Fault Current in ≤1μs
  • 0.5μs Turn-On and Reverse Turn-Off Time
  • Adjustable Current Limit with Circuit Breaker
  • Smooth Switchover without Oscillation
  • Adjustable Current Limit Fault Delay
  • Fault and Power Status Output
  • LTC4225-1: Latch Off After Fault
  • LTC4225-2: Automatic Retry After Fault
  • 24-Lead 4mm × 5mm QFN and SSOP Packages

Typical Application

LTC4225 Typical Application
LTC4225 Typical Application


The LTC®4225 offers ideal diode and Hot Swap™ functions for two power rails by controlling external series connected N-channel MOSFETs. MOSFETs acting as ideal diodes replace two high power Schottky diodes and the associated heat sinks, saving power and board area. Hot Swap control MOSFETs allow boards 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 current limit and internal timed circuit breaker.

The LTC4225 regulates the forward voltage drop across the back-to-back MOSFETs to ensure smooth current transfer from one supply to the other without oscillation. The ideal diodes turn on quickly to reduce the load voltage droop during supply switch-over. If the input supply fails or is shorted, a fast turn-off minimizes reverse-current transients.

The LTC4225 allows independent on/off control, and reports fault and power good status for the supply. The LTC4225-1 features a latch-off circuit breaker, while the LTC4225-2 provides automatic retry after a fault.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC4225CGN-1#PBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC4225CGN-1#TRPBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC4225CGN-2#PBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC4225CGN-2#TRPBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC4225CUFD-1#PBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4225CUFD-1#TRPBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4225CUFD-2#PBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4225CUFD-2#TRPBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4225IGN-1#PBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC4225IGN-1#TRPBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC4225IGN-2#PBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC4225IGN-2#TRPBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC4225IUFD-1#PBF 4x5 QFN-24 UFD I 05-08-1696 Yes
LTC4225IUFD-1#TRPBF 4x5 QFN-24 UFD I 05-08-1696 Yes
LTC4225IUFD-2#PBF 4x5 QFN-24 UFD I 05-08-1696 Yes
LTC4225IUFD-2#TRPBF 4x5 QFN-24 UFD I 05-08-1696 Yes

LTC4225 Package Drawing
LTC4225 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC4225CGN-1#PBF SSOP-24 C $5.13 $3.59 Yes
LTC4225CGN-1#TRPBF SSOP-24 C $3.65 Yes
LTC4225CGN-2#PBF SSOP-24 C $5.13 $3.59 Yes
LTC4225CGN-2#TRPBF SSOP-24 C $3.65 Yes
LTC4225CUFD-1#PBF 4x5 QFN-24 C $5.13 $3.59 Yes
LTC4225CUFD-1#TRPBF 4x5 QFN-24 C $3.65 Yes
LTC4225CUFD-2#PBF 4x5 QFN-24 C $5.13 $3.59 Yes
LTC4225CUFD-2#TRPBF 4x5 QFN-24 C $3.65 Yes
LTC4225IGN-1#PBF SSOP-24 I $5.64 $3.95 Yes
LTC4225IGN-1#TRPBF SSOP-24 I $4.01 Yes
LTC4225IGN-2#PBF SSOP-24 I $5.64 $3.95 Yes
LTC4225IGN-2#TRPBF SSOP-24 I $4.01 Yes
LTC4225IUFD-1#PBF 4x5 QFN-24 I $5.64 $3.95 Yes
LTC4225IUFD-1#TRPBF 4x5 QFN-24 I $4.01 Yes
LTC4225IUFD-2#PBF 4x5 QFN-24 I $5.64 $3.95 Yes
LTC4225IUFD-2#TRPBF 4x5 QFN-24 I $4.01 Yes
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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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1624A-A LTC4225-1 Dual Ideal Diode & Dual Hot Swap Controller with Latchoff after Fault $75.00
DC1624A-B LTC4225-2 Dual Ideal Diode & Dual Hot Swap Controller with Auto-Retry after Fault $75.00
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Click here to view our complete list of demo boards


  • Redundant Power Supplies
  • Supply Holdup
  • MicroTCA Systems and Servers
  • Telecom Networks
  • Power Prioritizer

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