LTC4222 - Dual Hot Swap Controller with I2C Compatible Monitoring


  • Allows Safe Insertion Into a Live Backplane
  • 10-Bit ADC Monitors Currents and Voltages
  • I2C/SMBus Interface
  • Wide Operating Voltage Range: 2.9V to 29V
  • dI/dt Controlled Soft-Start
  • High Side Drive for External N-Channel MOSFETs
  • No External Gate Capacitors Required
  • Input Overvoltage/Undervoltage Protection
  • Optional Latchoff or Auto-Retry After Faults
  • Alert Host After Faults
  • Inrush Current Limit with Foldback
  • Available in 32-Pin (5mm × 5mm) QFN and 36-Pin SSOP Packages

Typical Application

LTC4222 Typical Application
LTC4222 Typical Application


The LTC4222 Hot Swap controller allows two power paths to be safely inserted and removed from a live backplane. Using external N-channel pass transistors, board supply voltages and inrush currents are ramped up at an adjustable rate. An I2C interface and onboard ADC allows for monitoring of current, voltage and fault status for each channel.

The device features adjustable, analog, foldback current limit circuits and a Soft-Start circuit that sets the dI/dt of the inrush currents. An I2C interface may configure the part to latch off or automatically restart after the LTC4222 detects a fault on either channel.

The controller has additional features to interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a load card and power-up either automatically upon insertion or wait for an I2C command to turn on.


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
LTC4222CG#PBF SSOP-36 G C 05-08-1640 (G36) Yes
LTC4222CG#TRPBF SSOP-36 G C 05-08-1640 (G36) Yes
LTC4222CUH#PBF 5x5 QFN-32 UH C 05-08-1693 Yes
LTC4222CUH#TRPBF 5x5 QFN-32 UH C 05-08-1693 Yes
LTC4222IG#PBF SSOP-36 G I 05-08-1640 (G36) Yes
LTC4222IG#TRPBF SSOP-36 G I 05-08-1640 (G36) Yes
LTC4222IUH#PBF 5x5 QFN-32 UH I 05-08-1693 Yes
LTC4222IUH#TRPBF 5x5 QFN-32 UH I 05-08-1693 Yes

LTC4222 Package Drawing
LTC4222 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
LTC4222CG#PBF SSOP-36 C $8.36 $5.85 Yes
LTC4222CG#TRPBF SSOP-36 C $5.91 Yes
LTC4222CUH#PBF 5x5 QFN-32 C $8.36 $5.85 Yes
LTC4222CUH#TRPBF 5x5 QFN-32 C $5.91 Yes
LTC4222IG#PBF SSOP-36 I $10.03 $7.02 Yes
LTC4222IG#TRPBF SSOP-36 I $7.08 Yes
LTC4222IUH#PBF 5x5 QFN-32 I $10.03 $7.02 Yes
LTC4222IUH#TRPBF 5x5 QFN-32 I $7.08 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
DC1134A LTC4222 Demoboard: Dual Hot Swap Controller with I2C and ADC (Requires DC590) $75.00
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Companion Boards

Part Number Description Price Documentation
DC590B Isolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards $50.00
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Click here to view our complete list of demo boards


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