半导体学报2011，Vol.32Issue(10)：126-132,7.DOI:10.1088/1674-4926/32/10/105007
CMOS linear-in-dB VGA with DC offset cancellation for direct-conversion receivers
CMOS linear-in-dB VGA with DC offset cancellation for direct-conversion receivers
Lei Qianqian 1Chen Zhiming 1Shi Yin 2Chu Xiaojie 2Gong Zheng2
作者信息
- 1. Department of Electronic Engineering, Xi'an University of Technology, Xi'an 710048, China
- 2. Suzhou-CAS Semiconductors Integrated Technology Research Center, Suzhou 215021, China
- 折叠
摘要
Abstract
A low-power high-linearity linear-in-dB variable gain amplifier (VGA) with novel DC offset calibration loop for direct-conversion receiver (DCR) is proposed.The proposed VGA uses the differential-ramp based technique,a digitally programmable gain amplifier (PGA) can be converted to an analog controlled dB-linear VGA.An operational amplifier (OPAMP) utilizing an improved Miller compensation approach is adopted in this VGA design.The proposed VGA shows a 57 dB linear range.The DC offset cancellation (DCOC) loop is based on a continuous-time feedback that includes the Miller effect and a linear range operation MOS transistor to realize high-value capacitors and resistors to solve the DC offset problem,respectively.The proposed approach requires no external components and demonstrates excellent DCOC capability in measurement.Fabricated using SMIC 0.13 μm CMOS technology,this VGA dissipates 4.5 mW from a 1.2 V supply voltage while occupying 0.58 mm2 of chip area including bondpads.In addition,the DCOC circuit shows 500 Hz high pass cutoff frequency (HPCF) and the measured residual DC offset at the output of VGA is less than 2 mV.关键词
linear-in-dB/ VGA/ DC offset cancellationKey words
linear-in-dB/ VGA/ DC offset cancellation引用本文复制引用
Lei Qianqian,Chen Zhiming,Shi Yin,Chu Xiaojie,Gong Zheng..CMOS linear-in-dB VGA with DC offset cancellation for direct-conversion receivers[J].半导体学报,2011,32(10):126-132,7.
