Overview
Features and Benefits
- 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
Product Details
The LT3797 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.
Applications
- Automotive and Industrial Lighting
- RGB Lighting
- Billboards and Large Displays
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (3)
Documentation & Resources
-
DC1784B - Demo Manual7/24/2017
-
DC2218A - Demo Manual12/16/2015
-
DC1784A - Demo Manual1/21/2014
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
LT3797
Product Recommendations
LT3797 Companion Parts
Recommended Related Parts
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
| Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| LT3797ELXE#PBF | Material Declaration | Reliability Data | 48-Lead LQFP (7mm x 7mm w/ EP) | |
| LT3797EUKG#PBF | Material Declaration | Reliability Data | 52-Lead QFN (7mm x 8mm x 0.75mm w/ EP) | |
| LT3797EUKG#TRPBF | Material Declaration | Reliability Data | 52-Lead QFN (7mm x 8mm x 0.75mm w/ EP) | |
| LT3797ILXE#PBF | Material Declaration | Reliability Data | 48-Lead LQFP (7mm x 7mm w/ EP) | |
| LT3797IUKG#PBF | Material Declaration | Reliability Data | 52-Lead QFN (7mm x 8mm x 0.75mm w/ EP) | |
| LT3797IUKG#TRPBF | Material Declaration | Reliability Data | 52-Lead QFN (7mm x 8mm x 0.75mm w/ EP) | |
| Wafer Fabrication Data |
PCN-PDN Information
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Support & Discussions
LT3797 Discussions
Sample & Buy
Ordering FAQs
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Buy Now Pricing
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List Pricing
(*)The 1Ku 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 Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
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Sampling
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.