【摘要】 设计了一种应用于片外大电容场景下的具有快速瞬态响应特性的LDO。电路通过采用负载电流采样负反馈的结构构成了一个高带宽的电压缓冲器。该LDO使用具有电容倍增功能的共栅共源补偿结构，在外挂1μF负载电容的条件下，仅需500 fF的片上补偿电容即可保证在全负载范围内的稳定性。此外，通过使用自适应偏置技术，在减小轻载功耗的同时进一步提升了瞬态响应速度。电路采用0.18μm CMOS工艺进行设计与仿真验证。仿真结果表明，在LDO的输入电压为1.2 V、输出电压为1 V时，当负载电流以0.1μs的速度在150 mA和100μA之间切换时，最大电压变化仅为10.7 mV,输出电压恢复时间小于0.7μs。更多还原

【Abstract】 An LDO with fast transient response characteristics for off-chip large capacitance scenarios is proposed. The circuit was constituted with a high bandwidth voltage buffer by adopting the structure of negative feedback for load current sampling. A cascode compensation structure with capacitance multiplication function was used. Under the condition of external 1 μF load capacitance, only 500 fF on-chip compensation capacitance could ensure stability in the full load range. By using adaptive biasing technology, the transient response speed was further improved while reducing light-load power consumption. The circuit was designed and simulated in 0.18 μm CMOS process. The simulation results show that when the input voltage of the LDO is 1.2 V and the output voltage is 1 V, the overshoot and undershoot voltage are 10.7 mV and 8 mV respectively under a step load change from 150 mA to 100 μA within 0.7 μs.更多还原