LT3791: 60V 4-Switch Synchronous Buck-Boost LED Driver Controller Data Sheet5/22/2017405K
Features and Benefits
- 4-Switch Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT
- Synchronous Switching: Up to 98.5% Efficiency
- Wide VIN Range: 4.7V to 60V
- Wide VOUT Range: 0V to 60V (52V LED)
- ±6% LED Current Accuracy: 0V ≤ VLED < 52V
- True Color PWM™ and Analog Dimming
- LED and Input Current Regulation with Current Monitor Outputs
- No Top MOSFET Refresh in Buck or Boost
- VOUT Disconnected From VIN During Shutdown
- Open or Shorted LED Fault Protection
- Capable of 100W or Greater per IC
- 38-Lead TSSOP with Exposed Pad
The LT3791 is a synchronous 4-switch buck-boost LED driver controller. The controller can regulate LED current up to 52V of LED string with input voltages above, below, or equal to the output voltage. The constant-frequency, forced-continuous current mode architecture allows its frequency to be adjusted or synchronized from 200kHz to 700kHz. No top MOSFET refresh switching cycle is needed in buck or boost operation. With 60V input, 60V output capability and seamless transitions between operating regions, the LT3791 is ideal for LED driver applications in automotive, industrial, and even battery-powered systems.
For new designs we recommend the LT8391: 60V synchronous 4-switch, buck-boost LED controller due to its numerous performance improvements over the LT3791.
|LT3791||OPEN LED Pin|
|LT3791-1||Replaces OPEN LED Pin With C/10 Pin Termination Flag|
- Automotive Head Lamps/Running Lamps
- General Purpose Lighting
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 (1)
Demonstration circuit DC1666A is a synchronous four-switch buck-boost LED driver controller. It accepts an input voltage from 4.7V to 60V, and drives up to 25V of LEDs at 2A. DC1666A features both PWM and analog dimming of the LED string. It has an OPENLED flag that indicates when the LED string has been removed and it has a SHORTLED flag that indicates that the output has been shorted to GND. In both cases, the IC remains in control and well protected.
Documentation & Resources
R518 Reliability Data3/26/201834 K
DC1666A - Demo Manual4/2/2012305K
100W+, 98% Efficient Buck-Boost LED Driver12/6/2011478K
Tools & Simulations
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Models for the following parts are available in LTspice:
LT3791 Companion Parts
Recommended Related Parts
Recommended Suggested Oscillator
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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.