Linear 公司的LT3760是集成了升壓DC/DC控制器的 8路LED驅動器,能驅動高達45V的LED. 輸入電壓從6V 到 40V,40mA時的LED匹配電流為±2%,典型值為±0.7%,調光比高達3000:1,可編程的頻率從100kHz到1MHz,主要用于汽車,筆記本低電腦和TV監視器的背光.本文介紹LT3760主要特性, 方框圖, 36W, 28W, 15W,29W,25W以及14W LED驅動器應用電路.

The LTR3760 is an 8-channel LED driver with a step-up DC/DC controller capable of driving up to 45V of LEDs.

Each channel contains an accurate current sink with ±2% current matching. Channels follow a master programmable current to allow between 20mA to 100mA of LED current per string. Channels can be paralleled for higher LED current. Output voltage adapts to variations in LED VF for optimum efficiency and open LED faults do not affect the operation of connected LED strings.

The LT3760 allows a PWM dimming range up to 3000:1 and an analog dimming range up to 25:1. Operating frequency can be programmed from 100kHz up to 1MHz using a single resistor or synchronized to an external clock.

Additional features include: programmable maximum VOUT for open LED protection, a fault flag for open LED, programmable LED current derating vs temperature, micropower shutdown and internal soft-start. The LT3760 is available in a thermally enhanced 28-pin TSSOP Package.

LT3760主要特性:

Up to 45V of LEDsx 100mA,8-Channel LED Driver

Wide Input Range : 6V to 40V

±2% LED Current Matching at 40mA(Typ ±0.7%)

Up to 3000:1 True Color PWM™ Dimming Range

Single Resistor Sets LED Current (20mA to 100mA)

LED Current Regulated Even for PVIN > VOUT

Output Adapts to LED VF for Optimum Efficiency

Fault Flag + Protection for Open LED Strings

Protection for LED Pin to VOUT Short

Parallel Channels for Higher LED Current

Programmable LED Current Derating vs Temperature

Accurate Undervoltage Lockout Threshold with Programmable Hysteresis

Programmable Frequency (100kHz to 1MHz)

Synchronizable to an External Clock

LT3760應用:

Automotive, Notebook and TV Monitor Backlight


圖1.LT3760方框圖

圖2.效率92% 36W背光LED驅動器

圖3.效率92% 36W LED驅動器:1MHz升壓,8串LED,每串100mA


圖4.效率92% 28W LED驅動器:750kHz升壓,8串LED,每串80mA


圖5. 15W LED驅動器:750kHz升壓,8串LED,每串55mA


圖6. 29W LED驅動器:400kHz升壓,2串LED,每串350mA


圖7. 25W LED驅動器:400kHz升壓,3串LED,每串200mA


圖8. 28W LED驅動器:700kHz升壓,4串LED,每串160mA


圖9. 14W LED驅動器:700kHz升壓,4串LED,每串80mA


圖10. 28W LED驅動器:1MHz SPEIC,8串LED,每串100mA