中文摘要：

设计了一款电压随温度自适应变化,从而使驱动电流随温度自适应变化的过温保护电路。应用于LED驱动电路,具有滞回关断的特点,在恒流输出中增加温度自适应模块,设计简单而且比较稳定。基于0.5μm CMOS工艺,使用Cadence Spectre对电路进行仿真。仿真结果表明,基准电压精度高,温漂低,温度系数为1.6×10^-5/℃;LED电路在0～65℃,恒定输出350 mA,输出变化范围小于0.285%;在65～108℃范围内变化时,电流输出自适应范围为85 mA;在温度达到110℃时,关断信号为高电平,电路关断输出,直到温度下降到60℃时,电路重新开启。

英文摘要：

An overtemperature protection circuit is designed whose driving current changes with the voltage of temperature self- adaptive changes. Circuit has the characteristic of hysteresis thermal-shutdown and adds the temperature self-adaptive in the constant-current output. Circuit is simple and stable relatively.Based on 0.5 ~m standard CMOS technology,the circuit is simulated by Cadence Spectre. The result shows that the reference voltage with high precision,low temperature drift,and temperature coefficient is 1.6×10^-5/℃. The LED driver circuit current outputs 350 mA in 0-65 ℃ and its changeable range is under 0.285%. The variation range of temperature self-adaptive current is 85 mA when the temperature changes from 65 ℃ to 108 ℃. The signal for hysteresis thermal-shutdown would be high level and the output circuit would turn off when the temperature rises up to 110 ℃. The circuit wouldn＇t restart until the temperature down to 60 %.