Linear公司的LT3743具有三態(tài)控制的大電流20A效率92%LED驅(qū)動器,采用平均電流模式控制,PWM調(diào)光高達(dá)3000:1,電流調(diào)整精度6%,輸入電壓6V-36V,關(guān)斷電流小于1uA,具有輸出電壓調(diào)整和LED開路保護(hù)特性.主要應(yīng)用在DLP投映儀,大功率建筑照明和激光二極管.本文介紹了LT3743主要特性,方框圖,以及典型應(yīng)用電路,包括帶分流輸出的12V20ALED驅(qū)動電路和16-36V2ALED驅(qū)動電路,12V5A鋰電子充電電路和24V20A3-LED驅(qū)動電路.LT3743:HighCurrentSynchronousSt
Linear 公司的
LT3743具有三態(tài)控制的大
電流20A效率
92%
LED驅(qū)動器,采用平均電流模式控制,PWM調(diào)光高達(dá)
3000:1,電流調(diào)整精度6%,輸入電壓6V-36V,關(guān)斷電流小于1uA,具有輸出電壓調(diào)整和LED開路保護(hù)特性.主要應(yīng)用在DLP投映儀,大功率建筑照明和
激光二極管.本文介紹了LT3743主要特性,方框圖,以及典型應(yīng)用電路,包括帶分流輸出的
12V 20A LED驅(qū)動電路和
16-36V 2A LED驅(qū)動電路, 12V5A 鋰
電子充電電路和
24V 20A 3-LED驅(qū)動電路.
LT3743: High Current Synchr
onous Step-Down LED Driver with Three-State Control
The LT3743 is a fixed frequency synchronous step-down DC/DC controller designed to drive high current LEDs. The average current mode controller will maintain inductor current regulation over a wide output voltage range of 0V to (VIN – 2V). LED dimming is achieved through analog dimming on the CTRL_L, CTRL_H and CTRL_T
pins and with PWM dimming on the PWM and CTRL_SEL pins.
Through the use of externally switched load capacitors, the LT3743 is capable of changing regulated LED current levels within several &
mu;s, providing accurate, high speed PWM dimming between two current levels. The switching frequency is programmable from 200kHz to 1MHz through an external resistor on the RT pin.
Additional features include voltage regulation and overvoltage protection set with a voltage divider from the output to the FB pin. Overcurrent protection is provided and set by the CTRL_H pin.
LT3743主要特性:
PWM Dimming Provides Up to 3000:1 Dimming Ratio
CTRL_SEL Dimming Provides Up to 3000:1 Dimming Ratio Between Any Current
Three-State Current Control for Color Mixing
6% Current Regulation Accuracy
6V to 36V Input Voltage Range
Average Current Mode Control
2μs Maximum Recovery Time Between Any Current Regulation State
<1μA Shutdown Current
Output Voltage Regulation and Open-LED Protection
Thermally Enhanced 4
mmx?5mm QFN and 28-Pin FE Package
