摘要
介绍了一种基于0.6μmBiCMOS工艺的用于白光LED驱动电路的温度补偿技术,详细分析了该带隙基准电路的工作原理,并采用HSPICE软件对运算放大器和带隙基准源进行仿真。该技术充分利用了PN结反向饱和电流是温度敏感函数的特性,具有电路结构简单、温度特性好和电源抑制比高的特点。文章以理论公式的形式对整个模块的工作原理进行了分析,包括输出电压和输出电流,分析了失调电压对该电路的影响。从理论分析结果可以看出,该电路可以通过适当调节电阻之间的比例而得到温度特性好的输出电压和电流,以及输出可调的输出电压,还可以抑制失调噪声的影响。仿真结果表明,该电路的温度系数为2.8×10-5/K,电源抑制比在70dB以上,运放的低频电压增益约为78dB,电路功耗仅为0.05mW。所有的参数结果均满足了设计的要求。该带隙基准电路还可应用于其他电源芯片中。
A temperature compensation technology based on 0.6 μm BiCMOS process used for white LED drive circuit is presented. The mechanism of the band-gap circuit is well studied, and the characteristics of operation amplifier and band-gap voltage reference are simulated by Hspice. The sensitive temperature characteristic of PN junction inverse saturation current is fully utilized to obtain good temperature coefficient and PSRR with simple circuit structure. The mechanism of the circuit is described by expressions. We have deduced the expressions of the output voltage and current, and the influence of the input offset voltage is also considered. Apparently, not only good temperature coefficient and regulable output voltage, but also good temperature coefficient output current can be obtained by regulating some of the resistances. The input offset voltage can be restrained by this method also. The result of the emulator shows that the temperature coefficient of the band-gap voltage reference is 2.8×10^-5/K,and the PSRR is over 70 dB. The voltage gain of the amplifier is about 78 dB when working at low frequency. The power consumption of the whole circuit is only about 0.05 mW. It implies that all of the parameters have achieved the expectations. This band-gap voltage reference circuit can be widely used in other voltage regulator chips.
出处
《液晶与显示》
CAS
CSCD
北大核心
2008年第1期106-111,共6页
Chinese Journal of Liquid Crystals and Displays
基金
国家自然科学基金资助项目(No.50672030)
关键词
温度补偿
带隙基准
温度系数
电源抑制比
temperature compensation
band-gap reference
temperature coefficient
PSRR
