A switched-current third-order oversampling modulator with coupled differential replica FMC

Author

Sung, Guo-Ming ; Lai, Ying-Tzu ; Chang, Kuo-Hsuan

Author_Institution

Dept. of Electr. Eng., Nat. Taipei Univ. of Technol., Taipei, Taiwan

fYear

2012

Firstpage

1

Lastpage

5

Abstract

This paper presents a switched-current (SI) third-order sigma-delta modulator (SDM) which consists of a current-mode sample-and-hold (S/H) and a feedback topology to reduce the input impedance at input terminal, and a common-mode feed-forward (CMFF) circuit to improve the common-mode offset at output terminal. Besides, a SI feedback memory cell (FMC) with low clock feedthrough (CFT) error is presented with a coupled differential replica (CDR) topology. The proposed third-order SDM is designed and implemented with standard 0.35-μm CMOS technology. The simulation results show that the peak value of signal to noise plus distortion ratio (SNDR) is roughly 104.9 dB at the sampling rate of 10.24 MHz and the signal bandwidth of 80 kHz. However, the power dissipation of 33 mW is too large at power supply voltage of 2.5 V.

Keywords

CMOS integrated circuits; clocks; current-mode circuits; electric impedance; feedforward; modulators; network topology; sample and hold circuits; sampling methods; sigma-delta modulation; switched current circuits; CDR topology; CFT error; CMFF circuit; CMOS technology; S/H; SI SDM; SI feedback memory cell; SI third-order sigma-delta modulator; SNDR; bandwidth 80 kHz; clock feedthrough error; common-mode feed-forward circuit; common-mode offset; coupled differential replica FMC; coupled differential replica topology; current-mode sample-and-hold; feedback topology; frequency 10.24 MHz; impedance; output terminal; power 33 mW; power dissipation; sampling rate; signal bandwidth; signal to noise plus distortion ratio; size 0.35 mum; switched-current third-order oversampling modulator; third-order SDM; voltage 2.5 V; Clocks; Impedance; Modulation; Silicon; Switches; Switching circuits; Topology; Sigma-delta modulator; common-mode feed-forward; coupled differential replica; feedback memory cell; switched-current;

fLanguage

English

Publisher

ieee

Conference_Titel

Anti-Counterfeiting, Security and Identification (ASID), 2012 International Conference on

Conference_Location

Taipei

ISSN

2163-5048

Print_ISBN

978-1-4673-2144-0

Electronic_ISBN

2163-5048

Type

conf

DOI

10.1109/ICASID.2012.6325303

Filename

6325303