一种高压、宽输入的LDO电路设计

A high-voltage,wide-input LDO circuit design

为了满足在高压且大范围的电压条件下都能稳定输出一个电压,且有快速恢复时间和较小的过冲电压。本文基于华虹0.18μm BCD工艺设计了一款在高压下拥有宽范围输入电压8~40 V且在-50℃~165℃都能稳定输出5 V的LDO。并在带隙基准电路进行改进,采用无放大器的方法产生1.23 V的基准电压,温度系数达到10 ppm/℃。采取片外电容的方法和Buffer来分别提高电路的瞬态负载调整率和驱动电流,电路最大可驱动100 mA的负载。在负载为100 mA下,上冲电压和下冲电压也都分别为83 mV和79 mV,电压瞬态响应时间也在6μs左右。

In order to meet the high voltage and a wide range of voltage conditions,stable output voltage could be output,which has a fast recovery time and a small overshoot voltage.Based on Huahong 0.18μm BCD process,a LDO with a wide range of input voltage of 8~45 V under high voltage and stable output of 5 V at-50℃~165℃are designed in this paper.It is also improved in the bandgap reference circuit to generate a 1.23 V reference voltage without an amplifier,and the temperature coefficient reaches 10 ppm/℃.The off-chip capacitor method and Buffer are used to improve the transient load regulation rate and drive current of the circuit,respectively,and the circuit can drive up to 100 mA load.At a load of 100 mA,the upshoot voltage and downstroke voltage are also 83 mV and 79 mV,respectively,and the voltage transient response time is also about 6μs.