LTC1646 - CompactPCI Dual Hot Swap Controller


  • Allows Safe Board Insertion and Removal from a Live, CompactPCI™ Bus
  • Controls 3.3V and/or 5V Supplies
  • Programmable Foldback Current Limit During Power-Up
  • Dual Level Circuit Breakers Protect Supplies from Overcurrent and Short-Circuit Faults
  • Local_PCI_RST# Logic On-Chip
  • PRECHARGE Output Biases I/O Pins During Card Insertion and Extraction
  • User Programmable Supply Voltage Power-Up Rate
  • 15V High Side Drive for External N-Channels

Typical Application

LTC1646 Typical Application


The LTC1646 is a hot swap controller that allows a board to be safely inserted and removed from a live CompactPCI bus slot. Two external N-Channel transistors control the 3.3V and 5V supplies. The supplies can be ramped-up in current limit or at a programmable rate. Electronic circuit breakers protect both supplies against overcurrent fault conditions. The PWRGD output indicates when all of the supply voltages are within tolerance. The OFF/ON pin is used to cycle the board power or reset the circuit breaker. The PRECHARGE output can be used to bias the bus I/O pins during card insertion and extraction. PCI_RST# is logically combined on-chip with HEALTHY# in order to generate LOCAL_PCI_RST# which can be used to reset the CPCI card logic if either of the supply voltages is not within tolerance.

The LTC1646 is available in the 16-pin narrow SSOP package.


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
LTC1646CGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1646CGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1646IGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC1646IGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes

LTC1646 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
LTC1646CGN#PBF SSOP-16 C $4.65 $3.40 Yes
LTC1646CGN#TRPBF SSOP-16 C $3.46 Yes
LTC1646IGN#PBF SSOP-16 I $5.35 $3.90 Yes
LTC1646IGN#TRPBF SSOP-16 I $3.96 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
DC369A LTC1646CGN | Compact PCI-Bus Dual Hot-Swap Controller, 3.3V and 5V Inputs, 3.3Vout @ 7.6A, 5Vout @ 5A $50.00
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Click here to view our complete list of demo boards


  • CompactPCI Bus Removable Boards

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