LT3797 - Triple Output LED Driver Controller

Features

  • 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
  • 52-Lead QFN Package

Typical Application

LT3797 Typical Application

Description

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.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

QFN-52

LT3797 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT3797EUKG#PBF QFN 52 E $7.07 $4.95 View
LT3797EUKG#TRPBF QFN 52 E $5.01 View
LT3797IUKG#PBF QFN 52 I $7.91 $5.54 View
LT3797IUKG#TRPBF QFN 52 I $5.60 View
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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 2.5V to 40VIN to 1A Output at up to 50V LED Driver. $175.00
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Click here to view our complete list of demo boards

Applications

  • Automotive and Industrial Lighting
  • RGB Lighting
  • Billboards and Large Displays

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Design Tools

LTspiceIV

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Models for the following parts are available in LTspice IV:
LT3797

Technical Support