LTC4228-1/LTC4228-2 - Dual Ideal Diode and Hot Swap Controller


  • Power Path and Inrush Current Control for Redundant Supplies
  • Low Loss Replacement for Power Schottky Diodes
  • Protects Output Voltage from Input Brownouts
  • Allows Safe Hot Swapping from a Live Backplane
  • 2.9V to 18V Operating Range
  • Controls N-Channel MOSFETs
  • Limits Peak Fault Current in ≤1μs
  • Adjustable Current Limit with Circuit Breaker
  • Adjustable Current Limit Fault Delay
  • Smooth Switchover without Oscillation
  • 0.5μs Ideal Diode Turn-On and Turn-Off Time
  • Status, Fault and Power Good Outputs
  • LTC4228-1: Latch Off After Fault
  • LTC4228-2: Automatic Retry After Fault
  • 28-Lead 4mm × 5mm QFN and SSOP Packages

Typical Application

LTC4228 Typical Application
LTC4228 Typical Application


The LTC®4228 offers ideal diode and Hot Swap™ functions for two power rails by controlling two external N-channel MOSFETs in each rail. 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 LTC4228 regulates the forward voltage drop across the external MOSFETs and sense resistor 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 LTC4228 allows independent on/off control, and reports fault and power good status for the supply. The LTC4228 improves on the LTC4225 by recovering more quickly from input brownouts to preserve the output voltage.


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
LTC4228CGN-1#PBF SSOP-28 GN C 05-08-1641 (GN28) Yes
LTC4228CGN-1#TRPBF SSOP-28 GN C 05-08-1641 (GN28) Yes
LTC4228CGN-2#PBF SSOP-28 GN C 05-08-1641 (GN28) Yes
LTC4228CGN-2#TRPBF SSOP-28 GN C 05-08-1641 (GN28) Yes
LTC4228CUFD-1#PBF 4x5 QFN-28 UFD C 05-08-1712 Yes
LTC4228CUFD-1#TRPBF 4x5 QFN-28 UFD C 05-08-1712 Yes
LTC4228CUFD-2#PBF 4x5 QFN-28 UFD C 05-08-1712 Yes
LTC4228CUFD-2#TRPBF 4x5 QFN-28 UFD C 05-08-1712 Yes
LTC4228IGN-1#PBF SSOP-28 GN I 05-08-1641 (GN28) Yes
LTC4228IGN-1#TRPBF SSOP-28 GN I 05-08-1641 (GN28) Yes
LTC4228IGN-2#PBF SSOP-28 GN I 05-08-1641 (GN28) Yes
LTC4228IGN-2#TRPBF SSOP-28 GN I 05-08-1641 (GN28) Yes
LTC4228IUFD-1#PBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LTC4228IUFD-1#TRPBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LTC4228IUFD-2#PBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LTC4228IUFD-2#TRPBF 4x5 QFN-28 UFD I 05-08-1712 Yes

LTC4228 Package Drawing
LTC4228 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
LTC4228CGN-1#PBF SSOP-28 C $5.13 $3.59 Yes
LTC4228CGN-1#TRPBF SSOP-28 C $3.65 Yes
LTC4228CGN-2#PBF SSOP-28 C $5.13 $3.59 Yes
LTC4228CGN-2#TRPBF SSOP-28 C $3.65 Yes
LTC4228CUFD-1#PBF 4x5 QFN-28 C $5.13 $3.59 Yes
LTC4228CUFD-1#TRPBF 4x5 QFN-28 C $3.65 Yes
LTC4228CUFD-2#PBF 4x5 QFN-28 C $5.13 $3.59 Yes
LTC4228CUFD-2#TRPBF 4x5 QFN-28 C $3.65 Yes
LTC4228IGN-1#PBF SSOP-28 I $5.64 $3.95 Yes
LTC4228IGN-1#TRPBF SSOP-28 I $4.01 Yes
LTC4228IGN-2#PBF SSOP-28 I $5.64 $3.95 Yes
LTC4228IGN-2#TRPBF SSOP-28 I $4.01 Yes
LTC4228IUFD-1#PBF 4x5 QFN-28 I $5.64 $3.95 Yes
LTC4228IUFD-1#TRPBF 4x5 QFN-28 I $4.01 Yes
LTC4228IUFD-2#PBF 4x5 QFN-28 I $5.64 $3.95 Yes
LTC4228IUFD-2#TRPBF 4x5 QFN-28 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
DC1899A-A LTC4228-1 Demoboard | Dual Ideal Diode and Hot Swap Controller, Latchoff After Fault $75.00
DC1899A-B LTC4228-2 Demoboard | Dual Ideal Diode and Hot Swap Controller, Auto-Retry After Fault $75.00
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  • Redundant Power Supplies
  • MicroTCA Systems and Servers
  • Telecom Networks
  • Power Prioritizer

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