带有过温保护功能的1W白光LED驱动电路设计

Design of a 1W White LED Constant-Current Driver with Thermal-Shutdown Function

基于CSMC5V0.6μm标准CMOS工艺设计研制了一种具有过温保护功能的1 W温度传感LED恒流驱动电路。该电路由恒流驱动模块和温度传感模块组成,在电源电压为5V时能提供350 mA恒定驱动电流,并能在设定温度下关断功率MOS管,实现过温保护功能。恒流驱动模块采用比例电流采样方式,在电源电压正负变化10%范围内,驱动电流变化小于4.3%,温度传感模块利用PTAT(与绝对温度成正比)电压与基准电压比较,产生关断信号,关断温度在50℃—125℃范围内可由外接电阻设定。该芯片实现了温度传感模块和白光LED恒流驱动模块的单片集成,在LED照明技术中有一定的应用价值。

A 1 W white LED constant-current driver with thermal-shutdown function is designed and fabricated with 0. 6μm standard CMOS process provided by CSMC. It consists of constant-current driver module and temperature-sensor module. The circuit can provide constant 350 mA current with 5 V supply voltage and turn off the MOSFET when the chip＇s temperature is higher than the setting temperature. The constant-current driver module samples the current proportional to driving current to control the circuit. The output driving current changes less than 4. 3 % when supply voltage varies ±10 %. Temperature-sensor module compares the PTAT （Proportional To Absolute Temperature） voltage with reference voltage to general shutdown signal and turn off the circuit at setting temperature fixed by exterior resistor over the rage of 50 ℃-125 ℃. The chip is integrated the constant-current driver with temperature-sensor module and is valuable in LED lighting applications.