LT3753 - Active Clamp Synchronous Forward Controller


  • Input Voltage Range: 8.5V to 100V
  • Programmable Volt-Second Clamp
  • High Efficiency Control: Active Clamp, Synchronous Rectification, Programmable Delays
  • Short-Circuit (Hiccup Mode) Overcurrent Protection
  • Programmable Soft-Start/Stop
  • Programmable OVLO and UVLO with Hysteresis
  • Programmable Frequency (100kHz to 500kHz)
  • Synchronizable to an External Clock

Typical Application

LT3753 Typical Application


The LT®3753 is a current mode PWM controller optimized for an active clamp forward converter topology, allowing up to 100V input operation.

A programmable volt-second clamp allows primary switch duty cycles above 50% for high switch, transformer and rectifier utilization. Active clamp control reduces switch voltage stress and increases efficiency. A synchronous output is available for controlling secondary side synchronous rectification.

The LT3753 is available in a 38-lead plastic TSSOP package with missing pins for high voltage spacings.


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
LT3753EFE#PBF TSSOP-38 FE E 05-08-1865 Yes
LT3753EFE#TRPBF TSSOP-38 FE E 05-08-1865 Yes
LT3753HFE#PBF TSSOP-38 FE H 05-08-1865 Yes
LT3753HFE#TRPBF TSSOP-38 FE H 05-08-1865 Yes
LT3753IFE#PBF TSSOP-38 FE I 05-08-1865 Yes
LT3753IFE#TRPBF TSSOP-38 FE I 05-08-1865 Yes
LT3753MPFE#PBF TSSOP-38 FE MP 05-08-1865 Yes
LT3753MPFE#TRPBF TSSOP-38 FE MP 05-08-1865 Yes

LT3753 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
LT3753EFE#PBF TSSOP-38 E $4.29 $3.19 Yes
LT3753EFE#TRPBF TSSOP-38 E $3.25 Yes
LT3753HFE#PBF TSSOP-38 H $5.13 $3.80 Yes
LT3753HFE#TRPBF TSSOP-38 H $3.86 Yes
LT3753IFE#PBF TSSOP-38 I $4.70 $3.51 Yes
LT3753IFE#TRPBF TSSOP-38 I $3.57 Yes
LT3753MPFE#PBF TSSOP-38 MP $12.69 $9.80 Yes
LT3753MPFE#TRPBF TSSOP-38 MP $9.86 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
DC2050A LT3753EFE Isolated Demo Board | Sync Forward Controller with Active Clamp, 36V ≤ VIN ≤ 72V; VOUT = 5V @ 20A $200.00
DC2306A LT3753EFE Isolated Demo Board | Forward Converter, 10V ≤ VIN ≤ 54V; VOUT = 48V or 54V (Jumper Selectable) @ 1.5A $200.00
DC2324A-A LT3753EFE Demo Board | Isolated Forward Converter, 36V ≤ VIN ≤ 72V; VOUT = 24V @ 5A $200.00
DC2324A-B LT3753EFE Demo Board | Isolated Forward Converter, 18V ≤ VIN ≤ 36V; VOUT = 24V @ 5A $200.00
DC2324A-C LT3753EFE Isolated Demo Board | Sync Forward Controller with Active Clamp, 9V ≤ VIN ≤ 18V; VOUT = 24V @ 4A $200.00
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Click here to view our complete list of demo boards


  • Industrial, Automotive and Military Systems
  • 48V Telecommunication Isolated Power Supplies

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Design Tools


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