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
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
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 Drawing |
RoHS |
|---|---|---|---|---|---|
| LT3797EUKG#PBF | 7x8 QFN-52 | UKG | E | 05-08-1874 | Yes |
| LT3797EUKG#TRPBF | 7x8 QFN-52 | UKG | E | 05-08-1874 | Yes |
| LT3797IUKG#PBF | 7x8 QFN-52 | UKG | I | 05-08-1874 | Yes |
| LT3797IUKG#TRPBF | 7x8 QFN-52 | UKG | I | 05-08-1874 | Yes |
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 (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LT3797EUKG#PBF | 7x8 QFN-52 | E | $7.07 | $4.95 | Yes | |
| LT3797EUKG#TRPBF | 7x8 QFN-52 | E | $5.01 | Yes | ||
| LT3797IUKG#PBF | 7x8 QFN-52 | I | $7.91 | $5.54 | Yes | |
| LT3797IUKG#TRPBF | 7x8 QFN-52 | I | $5.60 | Yes | ||
| Buy Now • Request Samples | ||||||
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) | $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 | |
| Buy Now | |||
Applications
- Automotive and Industrial Lighting
- RGB Lighting
- Billboards and Large Displays
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Design Tools
LTspice
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LT3797
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.