为解决低压差线性稳压器(Low-dropout voltage regulator,LDO)的稳定性问题,提出了一种新的内部补偿策略。相比于传统的零极点跟踪补偿,这种新的补偿策略更容易实现足够的相位裕度。该LDO不需要外接ESR电容,只需一只2.2μF的瓷片电容就能实现稳定输出,尤适合便携式电子系统等应用场合。芯片采用1.5μm BCD(Bipolar-CMOS-DMOS)工艺设计和实现。测试结果表明,该LDO的线性调整率和负载调整率的典型值分别为4.8mV/V和45μV/mA。瞬态响应的最大超调量为70 mV。
To guarantee the stability of low-dropout voltage regulators(LDO),a new internal compensation scheme is proposed.Comparing with the conventional pole-zero tracking frequency compensation,the new scheme provides an easier solution for getting enough phase margin.The LDO is especially suitable for portable electronic systems since it can keep stable with only a 2.2 μF ceramic capacitor.The chip is implemented in 1.5 μm BCD technology.The experimental results show that the line and load regulation are 4.8 mV/V and 45 μV/mA respectively,while the overshoots are less than 70 mV.