摘要
提出了一种基于gm/ID方法设计的可变增益放大器。设计基于SMIC90nmCMOS工艺模型,可变增益放大器由一个固定增益级、两个可变增益级和一个增益控制器构成。固定增益级对输入信号预放大,以增加VGA最大增益。VGA的增益可变性由两个受增益控制器控制的可变增益级实现。运用gm/ID的综合设计方法,优化了任意工作范围内,基于gm/ID和VGS关系的晶体管设计,实现了低电压低功耗。为得到较宽的增益范围,应用了一种新颖的伪幂指函数。利用Cadence中spectre工具仿真,结果表明,在1.2 V的工作电压下,具有76 dB的增益,控制电压范围超过0.8 V,带宽范围从34 MHz到183.6 MHz,功耗为0.82 mW。
A variahle gain amplifier （VGA） was designed based on Gm/ID method. The circuit was fabricated by SMIC 90nm CMOS technology model. It consists of a fixed-gain stage, two variable-gain stages and a gain controller. The fixed gain stage gives pre-amplification in order to boost the VGA＇s maximum gain. The VGA＇s gain tenability is provided by the two variable gain stages which controlled by the gain controller. The design synthesis is simplified and optimized using gm/ID method which enables us to characterize transistors in any operating region based on their gm/ID and VGS relation, and help us to design the low-voltage low-power circuit. In order to get wider gain rage, the proposed VGA utilizes a novel pseudo-power exponential function. The Spectre simulation results show that under 1.2 V supply voltage the proposed VGA has 76 dB gain-range over 0.8 V control voltage range, with 34-183.6 MHz bandwidth, and 0.82 mW power consumption.
出处
《电子设计工程》
2012年第24期146-149,共4页
Electronic Design Engineering
