Dual Active-Feedback Frequency Compensation for Output-Capacitorless LDO With Transient and Stability Enhancement in 65-nm CMOS
Dual Active-Feedback Frequency Compensation for Output-Capacitorless LDO With Transient and Stability Enhancement in 65-nm CMOS
复制标题
用于无输出电容 LDO 的双有源反馈频率补偿，在 65 nm CMOS 中增强瞬态和稳定性
DOI：
10.1109/tpel.2019.2910557
复制
发表时间：
2020-01-01
影响因子：
6.7
通讯作者：
Chen, Dihu
中科院分区：
文献类型：
--
作者：
Li, Guangxiang;Qian, Huimin;Chen, Dihu
本文提出了一种采用双有源反馈频率补偿（DAFFC）技术的无输出电容低压差稳压器（OCL-LDO）。DAFFC方案由两个并联的有源反馈路径组成，这产生了两个极点-零点对，以有效地提高所提出的OCL-LDO的稳定性和瞬态响应。与传统的单通道有源反馈频率补偿方法相比，所提出的DAFFC技术在多部署一个有源反馈环的情况下提供了多一个设计自由度，并已被证明能够在相同的电容预算下获得更好的补偿效果。此外，由两个有源反馈回路产生的额外交流电流也增强了所提出的OCL-LDO的瞬态响应。为了证实所提出的DAFFC，需要用于误差放大器的伸缩式共源共栅输出级和两个片内补偿电容（分别为5 pF和1 pF）。建议的OCL-LDO已在65 nm CMOS工艺中实现，有源芯片面积为0.0105 mm2。输出电压为0.8 V，最小输入电压为0.95 V（100 mA负载电流）。该OCL-LDO在0~100 mA负载范围内稳定工作，静态电流为14 μ A。
An output-capacitorless low-dropout regulator (OCL-LDO) using a dual-active feedback frequency compensation (DAFFC) scheme with both transient and stability enhancement has been presented in this paper. The DAFFC scheme consists of two parallel active feedback paths, which creates two pole-zero pairs to effectively enhance the stability and transient response for the proposed OCL-LDO. Compared to the conventional single-path active-feedback frequency compensation method, the proposed DAFFC technique has provided one more design freedom with one more active feedback loop deployed and has been proved to be capable of obtaining better compensation effects with the same capacitor budget. Besides, the induced extra ac currents by the two active feedback loops have also enhanced the transient response of the proposed OCL-LDO. To substantiate the proposed DAFFC, a telescopic cascode output stage for error amplifier, and two on-chip compensation capacitors (5 and 1 pF, respectively) are needed. The proposed OCL-LDO has been implemented in 65-nm CMOS technology and the active chip area is 0.0105 mm2. The output voltage is 0.8 V, and the minimum input voltage is 0.95 V at 100-mA loading current. The proposed OCL-LDO can work stably in a load range of 0 to 100 mA with 14-μA quiescent current.