1. A chopper-stabilized high-pass Delta–Sigma Modulator with reduced chopper charge injection
- Author
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Kong-Pang Pun, Chi-Tung Ko, Yin-Sheng Zhao, and Siu-Kei Tang
- Subjects
Chopper ,Physics ,CMOS ,business.industry ,Dynamic range ,Amplifier ,General Engineering ,Electrical engineering ,Flicker noise ,business ,Delta-sigma modulation ,High-pass filter ,Chip - Abstract
In this paper, a chopper-stabilized high-pass Delta-Sigma Modulator (DSM) is reported with experimental results. A new circuit technique to suppress the residual offset caused by the chopper switch charge injection is proposed. Enabled by an amplifier sharing architecture, the technique diverts the error charge generated by the critical chopper to the second stage of the modulator such that the resulted error becomes first-order high-pass shaped. Fabricated in a [email protected] CMOS technology, the 2nd-order DSM realizes 82dB dynamic range over a 1kHz bandwidth while consuming [email protected] from a 1.8V supply. The offset is [email protected] and the flicker noise is invisible in the measured output spectrum down to 4Hz. The core area of the chip is 0.16mm^2.
- Published
- 2011