Linear LT3791升降壓100W LED驅(qū)動方案
Linear公司的LT3791是同步的四開關(guān)升壓-降壓LED驅(qū)動控制器,可使VIN高于,低于或等于VOUT,效率高達98.5%,輸入電壓4.7V-60V,輸出電壓0-60V,LED電流精度±6%,真彩色PWM和模擬調(diào)光,每個IC輸入功率100W或大于100W,主要用于汽車前燈/行駛燈和通用照明.本文介紹了LT3791主要特性,方框圖,多種應(yīng)用電路以及演示板DC1666A主要特性,電路圖,材料清單和PCB元件布局圖,測試電路圖.
he LT?3791 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.
The LT3791 provides input current monitor, LED current monitor, and open or shorted LED fault condition, during which the LT3791 either restarts or latches off.
LT3791主要特性:
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
LT3791應(yīng)用:
Automotive Head Lamps/Running Lamps
General Purpose Lighting
圖1.LT3791方框圖