LT3797 - Triple Output LED Driver Controller


  • Three Independent LED Driver Channels
  • Wide Input Voltage Range: 2.5V to 40V
  • VIN Transient Ride-Through Up to 60V
  • Rail-to-Rail LED Current Sense: 0V to 100V
  • 3000:1 PWM Dimming
  • TG Drivers for PMOS LED Disconnection
  • Operates in Boost, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology
  • Open-LED Protection
  • Short-Circuit Protected Boost Capable
  • Fault Flags for Independent Channels
  • Programmable VIN Undervoltage and Overvoltage Lockout
  • Adjustable Switching Frequency: 100kHz to 1MHz
  • Synchronizeable to an External Clock
  • CTRL Pins Provide Analog Dimming
  • Programmable Soft-Start
  • Low Profile 52-Lead 7mm x 8mm QFN and 48-Lead Exposed Pad LQFP

Typical Application

LT3797 Typical Application


The LT®3797 is a triple output DC/DC controller designed to drive three strings of LEDs. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. The LT3797 includes an integrated DC/DC converter to produce a regulated 7.5V supply for the N-channel MOSFET gate drivers of the three channels. This high efficiency converter enables the part to operate from a wide input voltage range from 2.5V to 40V. 

The LT3797 is designed so that each converter can use the most suitable configuration to drive its LED load, whether step-up, step-down or a combination. Two key features enable this flexibility: first the LT3797 can sense output current at the high side of the LED string; and second, the voltage feedback pin, FBH, is referred to the ISP current sensing input. The CTRL inputs provide output current analog dimming capability. The TG drivers level shift the PWM signals to drive the gates of external LED-disconnect P-channel MOSFETs, allowing high PWM dimming range, and providing LED overcurrent protection and short-circuit protected boost capability.


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
LT3797ELXE#PBF 7mm x 7mm LQFP-48 LXE E 05-08-1927 Yes
LT3797EUKG#PBF 7x8 QFN-52 UKG E 05-08-1874 Yes
LT3797EUKG#TRPBF 7x8 QFN-52 UKG E 05-08-1874 Yes
LT3797ILXE#PBF 7mm x 7mm LQFP-48 LXE I 05-08-1927 Yes
LT3797IUKG#PBF 7x8 QFN-52 UKG I 05-08-1874 Yes
LT3797IUKG#TRPBF 7x8 QFN-52 UKG I 05-08-1874 Yes

LT3797 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
LT3797ELXE#PBF 7mm x 7mm LQFP-48 E $7.07 $4.95 Yes
LT3797EUKG#PBF 7x8 QFN-52 E $7.07 $4.95 Yes
LT3797EUKG#TRPBF 7x8 QFN-52 E $5.01 Yes
LT3797ILXE#PBF 7mm x 7mm LQFP-48 I $7.91 $5.54 Yes
LT3797IUKG#PBF 7x8 QFN-52 I $7.91 $5.54 Yes
LT3797IUKG#TRPBF 7x8 QFN-52 I $5.60 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
DC1784A LT3797EUKG Demo Board | Triple Boost LED Driver, 2.5V ≤ VIN ≤ 40VIN, 50VLED @ 1A (x3) Contact Factory
DC1784B LT3797EUKG Demo Board: 2.5V to 40V input to 1A output at up to 50V $175.00
DC2218A LT3965EFE/LT3797 Demo Board | 2-String Buck LED Driver with Matrix LED Dimmer; 9V ≤ VIN ≤ 30V, Up to 30VLED @ 500mA (8 LEDs/String) $599.00
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Click here to view our complete list of demo boards


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Design Tools


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