LTC4215-1 and -3 - Hot Swap Controller with I2C Compatible Monitoring


  • Allows Safe Insertion into Live Backplane
  • 8-Bit ADC Monitors Current and Voltage
  • I2C/SMBus Interface
  • Wide Operating Voltage Range: 2.9V to 15V
  • dI/dt Controlled Soft-Start
  • Circuit Breaker Timeout: 20μs (LTC4215-1) or 420μs (LTC4215-3)
  • Three General Purpose Outputs
  • High Side Drive for External N-channel MOSFET
  • No External Gate Capacitor Required
  • Input Overvoltage/Undervoltage Protection
  • Optional Latchoff or Auto-Retry After Faults
  • Alerts Host After Faults
  • Inrush Current Limit with Foldback
  • Available in 24-Pin (4mm × 5mm) QFN

Typical Application

LTC4215-1 Typical Application
LTC4215-1 Typical Application


The LTC4215-1/LTC4215-3 Hot Swap™ controllers allow a board to be safely inserted and removed from a live backplane. Using an external N-channel pass transistor, board supply voltage and inrush current are ramped up at an adjustable rate. An I2C interface and onboard ADC allow for monitoring of load current, voltage and fault status.

The device features adjustable foldback current limit and a soft-start pin that sets the dI/dt of the inrush current. An I2C interface may configure the part to latch off or automatically restart after the LTC4215-1/LTC4215-3 detect a current limit fault.

The controller has additional features to interrupt the host when a fault has occurred, provide three general purpose outputs, 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.

The LTC4215-1 has a 20μs circuit breaker filter for applications that require a fast fault response time. The LTC4215-3 has an extended 420μs circuit breaker filter for applications where supply transients may exceed 20μs.

  Circuit Breaker Timeout
General Purpose Outputs
LTC4215 20us 1
LTC4215-1 20us 3
LTC4215-2 420us 1
LTC4215-3 420us 3


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
LTC4215CUFD-1#PBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4215CUFD-1#TRPBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4215CUFD-3#PBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4215CUFD-3#TRPBF 4x5 QFN-24 UFD C 05-08-1696 Yes
LTC4215IUFD-1#PBF 4x5 QFN-24 UFD I 05-08-1696 Yes
LTC4215IUFD-1#TRPBF 4x5 QFN-24 UFD I 05-08-1696 Yes
LTC4215IUFD-3#PBF 4x5 QFN-24 UFD I 05-08-1696 Yes
LTC4215IUFD-3#TRPBF 4x5 QFN-24 UFD I 05-08-1696 Yes

LTC4215-1 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
LTC4215CUFD-1#PBF 4x5 QFN-24 C $5.78 $3.95 Yes
LTC4215CUFD-1#TRPBF 4x5 QFN-24 C $4.01 Yes
LTC4215CUFD-3#PBF 4x5 QFN-24 C $5.78 $3.95 Yes
LTC4215CUFD-3#TRPBF 4x5 QFN-24 C $4.01 Yes
LTC4215IUFD-1#PBF 4x5 QFN-24 I $6.94 $4.74 Yes
LTC4215IUFD-1#TRPBF 4x5 QFN-24 I $4.80 Yes
LTC4215IUFD-3#PBF 4x5 QFN-24 I $6.94 $4.74 Yes
LTC4215IUFD-3#TRPBF 4x5 QFN-24 I $4.80 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
DC1243A LTC4215-1 Hot Swap Controller with ADC and 3 GPIO (req DC590) $100.00
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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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