设计了一种适用于流水线A/D转换器的全差分跨导放大器,通过采用单端放大器的增益增强方法,使运算放大器即具有较高的直流增益,又有较小的面积及较好的版图匹配性.通过对普通开关定容共模负反馈电路的改进,改善了建立时间减小了放大器输出共模的抖动.电路采用SMIC 0.18 μm CMOS工艺,并在Cadence下对电路及版图进行了仿真,结果表明:小信号低频电压增益119.3 dB;单位增益带宽378.1 MHz;相位裕度60°.%In this paper, a full differential transconductance amplifier suitable for pipelined ADC is presented. The gain-boost method of the single-ended gain-boost amplifier makes the operation amplifier have a high DC gain , smaller area and better territory match in layout. By using improved CMFB circuit, the settling time and jitter of output common-mode voltage are decreased. The whole circuit was simulated with SMIC 0. 18 μm CMOS technology. The result shows that DC-gain is 119. 3 dB, GBW is 378. 1 MHz and the phase margin is 60°.
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