一种超低静态电流LDO线性稳压器的设计

Design of an Ultra-Low Quiescent Current LDO Linear Regulator

为了延长便携式、可穿戴医疗设备的待机时间,设计了一种具有超低静态电流的低压差(LDO)线性稳压器。采用误差放大器与基准电路相结合的结构,在降低静态电流的同时减小芯片面积;其次,利用负载检测模块,降低了空载及轻载时过温保护和过流保护等模块的静态电流。采用自适应偏置电流技术来动态调整稳压环路各支路的工作电流以及零点频率补偿方式,解决了静态功耗与瞬态响应和环路带宽间的矛盾。该LDO线性稳压器采用0.35μm CMOS工艺进行流片加工,测试结果表明,该LDO线性稳压器静态电流为700 nA,最大负载电流为150 mA,轻载与满载跳变时上过冲电压为63 mV,下过冲电压为55 mV。

In order to extend the standby time of portable and wearable medical equipment,a low dropout(LDO)linear regulator with ultra-low quiescent current was designed.The structure of the error amplifier and the reference circuit was combined to reduce the chip area while reducing the quiescent current.Subsequently,the quiescent current of modules such as over-temperature protection and over-current protection under no load and light load was reduced by using the load detection module.Through the adaptive bias current technology which was adopted to dynamically adjust the working current of each branch of the voltage stabilizing loop and the zero frequency compensation method,the contradiction among quiescent power consumption,transient response and loop bandwidth was solved.The LDO linear regulator was fabricated with 0.35μm CMOS process.The test results show that the quiescent current of the LDO linear regulator is 700 nA,the maximum load current is 150 mA,the upper overshoot voltage is 63 mV and the lower overshoot voltage is 55 mV under light-load and full-load jumps.