一种增益可调CMOS恒带宽单片放大器

A CMOS Monolithic Constant-Bandwidth Amplifier

基于电流跟随器和负反馈原理，并结合电流镜像与虚地技术，得到了一种具有不依赖于闭环电压增益的１２０ｋＨｚ～８ＭＨｚ恒定带宽，增益０～６０ｄＢ可调，最高稳定工作频率５ＭＨｚ，功耗５．２ｍＷ的高性能ＣＭＯＳ放大器，其ＳＰＩＣＥ模拟表明，该放大器电气性能优越，模拟结果与理论分析比较吻合；可采用３～５μｍ硅栅ＣＭＯＳ工艺技术单片化集成实现，并可望用于宽带视频放大等模拟信号处理领域。

Based on current follower, negative feedback and current-mirror techniques,a CMOSamplifier with closed loop gain from 0 to 60dB,maximum stable operating friquency 5MHz andconsumption 5.2mW is proposed, which has a constan-bandwidth independent of the cllsed loop voltagegain. It is found that,for this high-performance amplifier,its theoretical anlyses are in agreement with thesimulation findings foud by SPICE program.It is very encouraging to be able to get monolithic chip of theamplifier by utilizing 3～5μm CMOS technologies and to be expected to applicatiOns in the field ofanalog signal processing such as vedio amplification.