一种利用前馈电容改善瞬态响应的LDO  

Optimization of the Transient Response for LDO with Feed-Forward Capacitance

作　　者：任国栋[1] 王永顺[2] 汪再兴[2] 王道斌[1] 冯有才[1] 武钢[1] 

机构地区：[1]兰州理工大学理学院,兰州730050 [2]兰州交通大学电子与信息工程学院,兰州730070

出　　处：《半导体技术》2011年第2期144-147,共4页Semiconductor Technology

基　　金：甘肃省科技支撑计划项目(097GKCA052);甘肃省自然科学基金项目(0960RJ2A091)

摘　　要：LDO具有高的纹波抑制和低噪声特点,在低输入输出压差以及RF领域应用广泛。在负载电流变化范围大的情况下,动态补偿成为必然选择。基于CSMC 0.5μm CMOS工艺,设计了一种利用MOS栅源电容实现动态补偿的LDO。采用反偏二极管模拟了寄生阱电容对系统稳定性的影响,并提出减小系统带宽、优化系统稳定性的方案。为了实现快速动态响应,设计前馈电容优化了系统。实验表明,设计的电路具有高PSRR和快速响应能力,适用于便携式设备供电。The LDO is a device of high ripple reject and low noise,and is wide used in low in-out differential pressure and RF.At the situation of a large range of the load current,a dynamic compensation was chosen.Based on CSMC 0.5 μm CMOS process,a dynamic compensation LDO with the MOS gate-source capacitance was designed.The well capacitance was simulated by a reverse-bias diode to imitate the effect on the system stability,and the stability of the system was optimized through reducing the bandwidth.The feed-forward capacitance was designed for quick response to improve the transient response characteristic.The experiment result shows that the circuit realizes the high PSRR and quick response,it is suitable for the portable devices.

关 键 词：阱电容 反偏二极管 前馈电容 低压差线性稳压器 带宽 

分 类 号：TN432[电子电信—微电子学与固体电子学]