一种衬底波纹注入的宽频带高PSR无片外电容LDO

A Wideband High-PSR Capless-LDO with Body-Ripple Injection

基于40 nm CMOS工艺,设计了一种具有高频高电源抑制(PSR)的无片外电容低压差线性稳压器(LDO)电路。电路采用1.1 V电源供电,LDO输出电压稳定在0.9 V。仿真结果表明,传统无片外电容LDO电路的PSR将会在环路的单位增益频率(UGF)处上升到一个尖峰,之后才经输出节点处的电容到地的通路开始降低,最高时PSR甚至大于0 dB。采用新型的衬底波纹注入技术的LDO能很好地抑制PSR的尖峰,可以做到全频段都在-20 dB以上,相比传统结构,尖峰处的PSR提高了20 dB以上。该LDO适用于需要低电压供电的射频电路。

A high-PSR capless-LDO circuit with body-ripple injection based on 40 nm CMOS IC process was designed.The circuit is powered by a 1.1 V power supply,and the LDO output voltage is stable at 0.9 V.Simulation results show that the PSR of conventional capless-LDO circuit increases to a peak at the UGF of the loop and then begin to decrease through the capacitor-to-ground path at the output node.The highest PSR is even greater than 0 dB.The LDO using the new substrate ripple injection technology can adequately suppress the PSR peak and achieve the entire frequency band above-20 dB.Compared with the conventional structure,the PSR at the peak increases by more than 20 dB.The LDO can be applied to RF circuits that require low voltage power supplies.