The LT3741's 6 V to 36 V input voltage range, constant current and constant voltage operation makes it ideal for a wide variety of applications, ranging from battery and supercap chargers and laser drivers to high current LED lighting. The LT3741 uses two external switching MOSFETs and delivers up to 20 A of continuous output current over a wide voltage range of 0 V to 34 V.

Efficiencies as high as 95 percent eliminate the need for external heat sinking. The LT3741's frequency can be programmed and synchronized between 200 kHz and 1 MHz, allowing designers to optimize efficiency while minimizing external component size. Combined with a 4 mm x 4 mm QFN-20 or thermally enhanced TSSOP-20 package, the LT3741 provides a highly compact constant voltage and current solution.

The LT3741 uses an average current mode control scheme to maintain inductor current regulation over a wide output voltage range of 0V to VIN-2V. The regulated current is set by an analog voltage on the CTRL pins and an external sense resistor.

The LT3741's topology enables it to both source and sink current. The LT3741's regulated output voltage and overvoltage protection are set with an external voltage divider. Additional features include an accurate external voltage reference, a programmable undervoltage lockout (ULVO) pin and thermal shutdown.

Summary Features LT3741
 

• Control Pin Provides Accurate Control of Regulated Output Current
•  
• ±1.5 percent Voltage Regulation Accuracy
•  
• ±6 percent Current Regulation Accuracy
•  
• 6 V to 36 V Input Voltage Range
•  
• Wide Output Voltage Range: 0 V to (VIN – 2 V)
•  
• Average Current Mode Control
•  
• <1 µA Shutdown Current
•  
• Up to 95 percent Efficiency
•  
• Additional Pin for Thermal Control of Load Current
•  
• Thermally Enhanced 4 mm × 4 mm QFN and 20-Pin FE Package.

Availability

The LT3741EUF is available in a 20-pin 4 mm x 4 mm QFN package and the LT3741EFE is available in a thermally enhanced TSSOP-20, priced starting at 3.95 and 4.10 US Dollars each, respectively in 1,000-piece quantities. Extended temperature versions, or “I” Grades, the LT3741IUF and LT3741IFE, are also available. Pricing starts at 4.65 and 4.82 US Dollars each, respectively in 1,000-piece quantities. All versions are available from stock.


Datasheet: LT3741