摘要
设计了高单位增益带宽积、大摆率、宽输出摆幅的运算放大器,该运算放采用了两级全差动结构.设计采用增加1个前馈放大级电路,以此产生1个左半平面零点并与第一个次极点相抵消的频率补偿方案,达到了环路稳定的要求.另外,提出一种新颖的共模反馈(CMFB)方案,使共模抑制比达到62dB,电路采用CSMC公司的0.5μm CMOS数模混合信号工艺设计并经过流片.测试结果表明,在单电源3.3 V电压下,运放的直流增益为65.5 dB,单位增益带宽积达350 MHz以及±2.7 V的输出摆幅.
A design methodology of high-speed operational amplifier (Op-amp) with high frequency of unity-gain bandwidth, high slew rate and large output swing is proposed. The structure with two-stage fully differential CMOS circuit was used in the op-amp, and the non-dominant pole was canceled by using a zero in left plane which is produced by adding a feed-forward amplify circuit. Moreover, obtain high stability of the common-mode, a novel CMFB structure is used. As a result, the value of CMRR was increased to be 62 dB. The chip is implemented by using CSMC 0.5 μm CMOS mixed-signal technology. The measurement results indicate that under the condition of supplied voltage of 3.3 V, the op-amp gets a DC voltage gain of 65.5 dB, unity-gain bandwidth of 350 MHz and output swing of ± 2.7 V.
出处
《江南大学学报(自然科学版)》
CAS
2008年第6期652-656,共5页
Joural of Jiangnan University (Natural Science Edition)
基金
浙江省重点科技计划项目(2007C2102)
关键词
运算放大器
高速
频率补偿
共模反馈
全差动
high-speed operational amplifier
frequency compensation
common-mode feedback
fully differential