LTC3255 - Wide VIN Range Fault Protected 50mA Step-Down Charge Pump


  • Input Voltage Range: 4V to 48V
  • Adjustable Regulated Output: 2.4V to 12.5V
  • Output Current: 50mA Maximum
  • 16μA Quiescent Current in Regulation at No Load
  • Input Fault Protection from –52V to 60V
  • Multimode Charge Pump (2:1, 1:1) with Automatic Mode Switching Maintains Regulation Over Wide VIN Range
  • Input Voltage Shunt Mode for Current-Fed Applications
  • Power Good Output
  • Overtemperature and Short-Circuit Protection
  • Operating Junction Temperature: 150°C Maximum
  • Thermally Enhanced 10-Lead MSOP and 10-Lead (3mm × 3mm) DFN packages

Typical Application

LTC3255 Typical Application
LTC3255 Typical Application


The LTC®3255 is a switched-capacitor step-down DC/DC converter that produces a regulated output (2.4V to 12.5V adjustable) from a 4V to 48V input. In applications where the input voltage exceeds twice the output voltage, 2:1 capacitive charge pumping extends output current capability beyond input supply current limits. At no load, Burst Mode® operation cuts VIN quiescent current to 16μA.

With its integrated VIN shunt regulator, the LTC3255 excels in 4mA to 20mA current loop applications. The device enables current multiplication; a 4mA input current can power a 7.4mA load continuously. Alternatively, the LTC3255 serves as a higher efficiency replacement for linear regulators and provides a space-saving inductorfree alternative to buck DC/DC converters.

The LTC3255 withstands reverse-polarity input supplies and output short-circuits without damage. Safety features including current limit and overtemperature protection further enhance robustness. The LTC3255 is available in thermally enhanced 10-lead MSOP and low profile 3mm × 3mm 10-lead DFN packages.


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
LTC3255EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC3255EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC3255EMSE#PBF MS-10E MSE E 05-08-1664 Yes
LTC3255EMSE#TRPBF MS-10E MSE E 05-08-1664 Yes
LTC3255HDD#PBF 3x3 DFN-10 DD H 05-08-1699 Yes
LTC3255HDD#TRPBF 3x3 DFN-10 DD H 05-08-1699 Yes
LTC3255HMSE#PBF MS-10E MSE H 05-08-1664 Yes
LTC3255HMSE#TRPBF MS-10E MSE H 05-08-1664 Yes
LTC3255IDD#PBF 3x3 DFN-10 DD I 05-08-1699 Yes
LTC3255IDD#TRPBF 3x3 DFN-10 DD I 05-08-1699 Yes
LTC3255IMSE#PBF MS-10E MSE I 05-08-1664 Yes
LTC3255IMSE#TRPBF MS-10E MSE I 05-08-1664 Yes
LTC3255MPDD#PBF 3x3 DFN-10 DD MP 05-08-1699 Yes
LTC3255MPDD#TRPBF 3x3 DFN-10 DD MP 05-08-1699 Yes
LTC3255MPMSE#PBF MS-10E MSE MP 05-08-1664 Yes
LTC3255MPMSE#TRPBF MS-10E MSE MP 05-08-1664 Yes

LTC3255 Package Drawing
LTC3255 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
LTC3255EDD#PBF 3x3 DFN-10 E $3.29 $2.30 Yes
LTC3255EDD#TRPBF 3x3 DFN-10 E $2.36 Yes
LTC3255EMSE#PBF MS-10E E $3.29 $2.30 Yes
LTC3255EMSE#TRPBF MS-10E E $2.36 Yes
LTC3255HDD#PBF 3x3 DFN-10 H $4.22 $2.95 Yes
LTC3255HDD#TRPBF 3x3 DFN-10 H $3.01 Yes
LTC3255HMSE#PBF MS-10E H $4.22 $2.95 Yes
LTC3255HMSE#TRPBF MS-10E H $3.01 Yes
LTC3255IDD#PBF 3x3 DFN-10 I $3.71 $2.60 Yes
LTC3255IDD#TRPBF 3x3 DFN-10 I $2.66 Yes
LTC3255IMSE#PBF MS-10E I $3.71 $2.60 Yes
LTC3255IMSE#TRPBF MS-10E I $2.66 Yes
LTC3255MPDD#PBF 3x3 DFN-10 MP $10.00 $7.00 Yes
LTC3255MPDD#TRPBF 3x3 DFN-10 MP $7.06 Yes
LTC3255MPMSE#PBF MS-10E MP $10.00 $7.00 Yes
LTC3255MPMSE#TRPBF MS-10E MP $7.06 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
DC2041A LTC3255EMSE Demo Board | -52V/60V Fault-Protected Step-Down Charge Pump, 4V ≤ VIN ≤ 48V, Vout = 2.5V/3.3V/5V/12V/Adj @ 50mA $100.00
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  • Current-Boosting Voltage Regulators for 4mA to 20mA Current Loops

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