一种带共模反馈电路的套筒式全差分运算放大器.pdfVIP

41 3 Vol. 41, No. 3 2011 6 Micr oelectr onics Jun. 2011 成东波, 孙玲玲, 洪 慧, 章少杰, 吴国峰 ( , 310018) : 基于Chartered 0.35 工艺, 设计了一种带共模反馈电路的套 式全差分运算放大 器该电路主要由套 式结构的主运放偏置电路和共模反馈电路组成仿真结果表明,设计的电 路开环增益为79.4 dB, 单位增益带宽为179 MHz, 相位裕度为75.5( 负载 Cload = 3 pF) , 功耗为 2.31 W提出了一种全新的全差分运放增益测试方法, 可以比较准确地测得运放的低频增益 对通过流片的电路进行测试和分析, 结果与仿真指标基本接近, 达到预先设计的要求 : 套 式结构; 运算放大器; 共模反馈电路 :T N492 :A : 2011) A Telescopic Fully Differential A plifier with CMFB Circuit CHENG Dongbo, SUN Lingling, HONG Hui, ZHANG Shaojie, WU Guofeng (K ey L aboratory of RF Circuit System of Ministry of Education, H angz hou ianz i University, H angz hou 310018, P. R. China ) Abstract: Based on Chartered 0. 35 process, a telescopic fully differential a plifier with CMFB circuit was designed. T he circuit was co posed of a telescopic a plifier, a biasing circuit and a CM FB circuit. Si ulation results showed that the a plifier had an openloop gain of 79. 4 dB, a unitygain bandwidth of 179 MHz, and a phase argin of 75.5at a capacitive load of 3 pF, and it dissipated a power of 2. 31 W. Moreover, a new open loop gain test circuit was proposed to accurately test low frequency gain of thefully differential operational a plifier. Finally, thetapeout a plifier was tested and analyzed, and results indicated that theproposed a plifier achieved its design goal in general. Key words: Telescopic structure; Operational a plifier; CMFB circuit EEACC: 2570D , [ 1] 1 引言