A high-speed fully differential current switch

Author

Luh, Louis ; Choma, John, Jr. ; Draper, Jeffrey

Author_Institution

Inf. Sci. Inst., Univ. of Southern California, Marina del Rey, CA, USA

Volume

47

Issue

4

fYear

2000

fDate

4/1/2000 12:00:00 AM

Firstpage

358

Lastpage

363

Abstract

A high-speed differential-mode current switch is presented. The clock-feedthrough effect is reduced by swing-reduced drivers (SRD´s) and neutralized by dummy transistors. With the use of SRD´s, the switching transistors never operate in the triode region, which provides good matching of capacitance between the switching transistors and dummy transistors. The SRD´s also reduce the possible large current spikes on the outputs of the current switch. Analysis shows this current switch is ideal for high-speed current-mode signal processing. A continuous-time switched-current ΣΔ modulator using these current switches has been implemented in a 2 μm CMOS process and achieved a 59 dB dynamic range with a 50 MHz clock

Keywords

CMOS analogue integrated circuits; analogue processing circuits; current-mode circuits; field effect transistor switches; high-speed integrated circuits; sigma-delta modulation; switched current circuits; switching circuits; 2 micron; 50 MHz; CMOS process; SI sigma-delta modulator; capacitance matching; clock-feedthrough effect reduction; continuous-time SI ΣΔ modulator; current-mode signal processing; dummy transistors; fully differential current switch; high-speed current switch; swing-reduced drivers; switched-current ΣΔ modulator; switching transistors; Capacitance; Clocks; Control systems; Coupling circuits; Error correction; MOSFETs; Signal processing; Switches; Switching circuits; Voltage control;

fLanguage

English

Journal_Title

Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1057-7130

Type

jour

DOI

10.1109/82.839672

Filename

839672