A digitally controlled AGC loop circuitry for GNSS receiver chip with a binary weighted accurate dB-linear PGA  

作　　者：靳刚 庄奕琪 阴玥 崔淼 

机构地区：[1]Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University

出　　处：《Journal of Semiconductors》2015年第3期114-120,共7页半导体学报（英文版）

摘　　要：A novel digitally controlled automatic gain control （AGC） loop circuitry for the global navigation satel- lite system （GNSS） receiver chip is presented. The entire AGC loop contains a programmable gain amplifier （PGA）, an AGC circuit and an analog-to-digital converter （ADC）, which is implemented in a 0.18 μm complementary metal--oxide-semiconductor （CMOS） process and measured. A binary-weighted approach is proposed in the PGA to achieve wide dB-linear gain control with small gain error. With binary-weighted cascaded amplifiers for coarse gain control, and parallel binary-weighted trans-conductance amplifier array for fine gain control, the PGA can provide a 64 dB dynamic range from -4 to 60 dB in 1.14 dB gain steps with a less than 0.15 dB gain error. Based on the Gaussian noise statistic characteristic of the GNSS signal, a digital AGC circuit is also proposed with low area and fast settling. The feed-backward AGC loop occupies an area of 0.27 mm^2 and settles within less than 165 μs while consuming an average current of 1.92 mA at 1.8 V.A novel digitally controlled automatic gain control （AGC） loop circuitry for the global navigation satel- lite system （GNSS） receiver chip is presented. The entire AGC loop contains a programmable gain amplifier （PGA）, an AGC circuit and an analog-to-digital converter （ADC）, which is implemented in a 0.18 μm complementary metal--oxide-semiconductor （CMOS） process and measured. A binary-weighted approach is proposed in the PGA to achieve wide dB-linear gain control with small gain error. With binary-weighted cascaded amplifiers for coarse gain control, and parallel binary-weighted trans-conductance amplifier array for fine gain control, the PGA can provide a 64 dB dynamic range from -4 to 60 dB in 1.14 dB gain steps with a less than 0.15 dB gain error. Based on the Gaussian noise statistic characteristic of the GNSS signal, a digital AGC circuit is also proposed with low area and fast settling. The feed-backward AGC loop occupies an area of 0.27 mm^2 and settles within less than 165 μs while consuming an average current of 1.92 mA at 1.8 V.

关 键 词：PGA binary-weighted AGC loop GNSS Gaussian noise 

分 类 号：TN965.5[电子电信—信号与信息处理]