A chopper-stabilized amplifier for input signal amplification of sigma-delta ADC

Author

Honghui Deng ; Zhangmeng Wang

Author_Institution

Inst. of VLSI Design, Hefei Univ. of Technol., Hefei, China

fYear

2014

Firstpage

1

Lastpage

4

Abstract

This paper proposes a full differential and low-noise chopper-stabilized amplifier for input signal amplification of sigma-delta analog to digital converter (ADC). Based on chopper stabilizing and dynamic matching techniques, folded-cascode structure with class AB output stage is adopted and chopper switches are used at low-resistance nodes in the current paths to improve the signal bandwidth and output voltage swing. The simulation results based on chartered 0.35um CMOS process show that with the power supply of 3.3V, the chopper-stabilized amplifier has open-loop gain of 84 dB and gain bandwidth (GBW) of 483 kHz. Between 1 Hz and 1 kHz, the input equivalent noise is 1.6uV/√hz without chopper signals and is reduced to 40nV/√hz after chopper signals of 38.4 kHz are added.

Keywords

CMOS integrated circuits; analogue-digital conversion; choppers (circuits); differential amplifiers; low noise amplifiers; sigma-delta modulation; CMOS process; GBW; analog to digital converter; bandwidth 483 kHz; chopper signal; chopper switch; class AB output stage; current path; differential amplifier; dynamic matching technique; equivalent noise; folded-cascode structure; gain 84 dB; gain bandwidth; input signal amplification; low-noise chopper-stabilized amplifier; low-resistance node; output voltage swing; power supply; sigma-delta ADC; signal bandwidth; size 0.35 mum; voltage 3.3 V; Chopper-stabilized amplifier; Class AB output stage; Low noise; Sigma-delta ADC;

fLanguage

English

Publisher

ieee

Conference_Titel

Anti-counterfeiting, Security, and Identification (ASID), 2014 International Conference on

Print_ISBN

978-1-4799-7117-6

Type

conf

DOI

10.1109/ICASID.2014.7064968

Filename

7064968