一种快速瞬态响应的无片外电容LDO稳压器设计

Design of a Fast Transient Response and Capacitor-Free LDO Regulator

摘要: 基于LDO稳压器的工作原理, 设计了一种快速瞬态响应的无片外电容LDO稳压器电路.LDO稳压器主要包括无运放带隙基准源、误差放大器、瞬态响应增强模块、功率调整管及NMOS管反馈网络.提出一种新结构的瞬态响应增强电路, 加快功率调整管栅极的充放电速度, 实现了快速瞬态响应.电路采用TSMC 0.18 μm标准CMOS工艺实现, 版图尺寸为190 μm×210 μm, 后仿真结果表明: 在输入电压为3.3 V时, 输出电压为2.15 V, 轻载与满载之间跳变的建立时间最大为0.6 μs, 低频时PSRR为-63 dB, 压差为50 mV.

Abstract: Based on the working principle of LDO regulator, a fast transient response and capacitor-free LDO regulator was designed. LDO regulator includes bandgap reference without amplifier、EA、transient response enhancement module、power regulator and NMOS transistor feedback network. A new structure of the transient response enhancement circuit is proposed to speed up the power adjustment transistor gate charge and discharge, and realize the fast transient response. The circuit is fabricated with TSMC 0.18μm CMOS process and has the layout size of 190 μm×210 μm. The simulation results show that when the input voltage is 3.3 V, the output voltage is 2.15 V. Between light load and full load establishment of the maximum time for the 0.6 μs. PSRR is -63 dB at low frequency, voltage difference is 50 mV.