LTC1644 - CompactPCI Bus Hot Swap Controller


  • Allows Safe Board Insertion and Removal from a Live, CompactPCI™ Bus
  • Controls –12V, 3.3V, 5V and 12V Supplies
  • Adjustable Foldback Current Limit with Circuit Breaker
  • Dual-Level Circuit Breakers Protect 5V and 3.3V Supplies from Overcurrent and Short-Circuit Faults
  • LOCAL_PCI_RST# Logic On-Chip
  • PRECHARGE Output Biases I/O Pins During Card Insertion and Extraction
  • Adjustable Supply Voltage Power-Up Rate

Typical Application

LTC1644 Typical Application


The LTC®1644 is a Hot Swap™ controller that allows a board to be safely inserted and removed from a CompactPCI bus slot. External N-channel transistors control the 3.3V/5V supplies, while on-chip switches control the –12V and 12V supplies. The 3.3V and 5V supplies can be ramped up at a programmable rate. Electronic circuit breakers protect all four supplies against overcurrent faults. 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 combined on-chip with HEALTHY# in order to generate LOCAL_PCI_RST#.


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
LTC1644CGN#PBF SSOP-20 GN C 05-08-1641 (GN20) Yes
LTC1644CGN#TRPBF SSOP-20 GN C 05-08-1641 (GN20) Yes
LTC1644IGN#PBF SSOP-20 GN I 05-08-1641 (GN20) Yes
LTC1644IGN#TRPBF SSOP-20 GN I 05-08-1641 (GN20) Yes

LTC1644 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
LTC1644CGN#PBF SSOP-20 C $4.55 $3.60 Yes
LTC1644CGN#TRPBF SSOP-20 C $3.70 Yes
LTC1644IGN#PBF SSOP-20 I $5.20 $4.15 Yes
LTC1644IGN#TRPBF SSOP-20 I $4.65 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
DC461A LTC1644 demo board $25.00
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Click here to view our complete list of demo boards


  • Hot Board Insertion into CompactPCI Bus

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