一种应用乒乓自归零的高精度放大器  

A high-precision amplifier using ping-pong auto-zeroing

作　　者：邓新伟 杨尚争 毛佳烽 胡伟波 任立儒[1] Deng Xinwei;Yang Shangzheng;Mao Jiafeng;Hu Weibo;Ren Liru(College of Electronic Information and Optical Engineering,Nankai University,Tianjin 300350,China)

机构地区：[1]南开大学电子信息与光学工程学院,天津300350

出　　处：《电子技术应用》2025年第3期49-53,共5页Application of Electronic Technique

摘　　要：设计实现了一种低失调、高增益的运算放大器(运放)。整体电路包含带隙基准、振荡器、分频器、辅助运放和主运放等。该电路采用乒乓结构的自归零技术,实现了连续工作,同时显著缩减了放大器的输入失调偏移。此外,还提出了一种新颖、高效的控制时序,以较低的成本有效降低了放大器在乒乓切换过程中的稳定时间,进一步减小了放大器的输出毛刺。该放大器芯片基于350 nm CMOS工艺设计制造,实际测试结果表明,在5 V电源电压下,放大器消耗了0.65 mA的电流,实现了最大3µV的输入失调偏移,增益带宽积为8 MHz,噪声频谱密度降到了30 nV/√Hz。This paper presents the design and implementation of a low-offset,high-gain operational amplifier(op-amp).The overall circuit consists of a bandgap reference,oscillator,frequency divider,auxiliary op-amp,and main op-amp.By employing a ping-pong auto-zeroing architecture,the circuit achieves continuous operation while significantly reducing the input offset voltage of the amplifier.Furthermore,this paper proposes a novel and efficient control timing scheme that effectively reduces the settling time during ping-pong switching at a relatively low cost,further minimizing the output glitches of the amplifier.The amplifier chip was designed and fabricated in a 350 nm CMOS process.Measurement results demonstrate that under a 5 V supply voltage,the amplifier consumes 0.65 mA current,achieves a maximum input offset voltage of 3μV,provides a gain-bandwidth product of 8 MHz,and exhibits a noise spectral density as low as 30 nV/√Hz.

关 键 词：低失调 乒乓 自归零 放大器 

分 类 号：TN402[电子电信—微电子学与固体电子学]