LTC1643A - PCI-Bus Hot Swap Controller


  • Allows Safe Board Insertion and Removal from a Live PCI Slot
  • Works on either a Motherboard (LTC1643AH) or CompactPCI™ Card (LTC1643AL/LTC1643AL-1)
  • Controls –12V, 3.3V, 5V, 12V Supplies
  • Programmable Foldback Current Limit with Circuit Breaker
  • User-Programmable Supply Voltage Power-Up Rate
  • High Side Drive for External N-Channels MOSFETs
  • –12V and 12V On-Chip Switches
  • Fault and Power-Good Outputs
  • Available in a Narrow 16-Lead SSOP Package

Typical Application

LTC1643A Typical Application


The LTC1643A is a Hot Swap controller that allows a board to be safely inserted and removed from a live PCI-Bus slot. Two external N-channel transistors control the 3.3V and 5V supplies while on-chip switches control the –12V and 12V supplies. All supply voltages can be ramped up at a programmable rate. An electronic circuit breaker protects all four supplies against overcurrent faults. The foldback current limit feature limits current spikes and power dissipation when shorts occur and allows boards with large capacitances to be powered up without tripping the circuit breaker. The PWRGD output indicates when all of the supply voltages are within tolerance and the FAULT output indicates an overcurrent condition. The ON(LTC1643AH)/ON (LTC1643AL/ LTC1643AL-1) pin is used to cycle the board power or reset the circuit breaker. The LTC1643AL-1 has the ±12V power good comparators disabled.

The LTC1643A is available in a 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
LTC1643AHCGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1643AHCGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1643AHIGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC1643AHIGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC1643AL-1CGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1643AL-1CGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1643AL-1IGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC1643AL-1IGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC1643ALCGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1643ALCGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC1643ALIGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC1643ALIGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes

LTC1643A 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
LTC1643AHCGN#PBF SSOP-16 C $5.00 $4.25 Yes
LTC1643AHCGN#TRPBF SSOP-16 C $4.31 Yes
LTC1643AHIGN#PBF SSOP-16 I $5.70 $4.85 Yes
LTC1643AHIGN#TRPBF SSOP-16 I $4.91 Yes
LTC1643AL-1CGN#PBF SSOP-16 C $5.00 $4.25 Yes
LTC1643AL-1CGN#TRPBF SSOP-16 C $4.31 Yes
LTC1643AL-1IGN#PBF SSOP-16 I $5.70 $4.85 Yes
LTC1643AL-1IGN#TRPBF SSOP-16 I $4.91 Yes
LTC1643ALCGN#PBF SSOP-16 C $5.00 $4.25 Yes
LTC1643ALCGN#TRPBF SSOP-16 C $4.31 Yes
LTC1643ALIGN#PBF SSOP-16 I $5.70 $4.85 Yes
LTC1643ALIGN#TRPBF SSOP-16 I $4.91 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.

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