A High Gain CMOS Closed Loop Variable Gain Amplifier with Digital AGC Circuits  

作　　者：GAO Darning YE Qing YE Tianchun 

机构地区：[1]Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China

出　　处：《Chinese Journal of Electronics》2006年第4期604-607,共4页电子学报（英文版）

摘　　要：A closed loop CMOS Variable gain amplifier （VGA） with high gain and digital automatic gain control circuits （AGC loop） is designed using SMIC 0.18μm CMOS mixed technology, which has a programmable output AC voltage to adapt well to dynamic range of different application solution. The digital AGC loop is usually implemented in basic band DSP chip, however, a digital AGC loop separated from DSP chip is discussed here, which has a new architecture. The separated AGC loop makes VGA and DSP devote mind to themselves work respectively. As a result, a closed loop VGA with 30MHz. operation frequency is given, and its programmable output AC voltage Vp-p can change from 150mV to 500mV every 50inV. This VGA has a high gain, and it can adjust its gain automati- cally from 85dB to 55dB. Its NF is about 6dB.

关 键 词：CMOS IFIC Variable gain amplifler Automatic gain control circuits Basic band DSP. 

分 类 号：TN79[电子电信—电路与系统]