Title :
A transistor-only current-mode ΣΔ modulator
Author :
Daubert, Steven J. ; Vallancourt, David
Author_Institution :
AT&T Bell Lab., Allentown, PA, USA
fDate :
5/1/1992 12:00:00 AM
Abstract :
Current copier circuits are used in the IC realization of a transistor-only second-order ΣΔ modulator. By using current copiers, it is possible to implement the modulator without using linear capacitors, as is required for switched-capacitor approaches. Design considerations based on settling time and noise for a current copier circuit are presented, along with the description of the current output D/A and the current quantizer. The modulator has been fabricated in a 0.9-μm digital CMOS process and achieves 13-b resolution and 12-b linearity over the voiceband frequency range
Keywords :
CMOS integrated circuits; digital-analogue conversion; modulators; ΣΔ modulator; 0.9 micron; IC realization; current copier circuit; current quantizer; current-mode; digital CMOS process; noise; second-order; settling time; sigma-delta modulator; transistor-only; CMOS process; CMOS technology; Chirp modulation; Delta modulation; Delta-sigma modulation; Digital modulation; Parasitic capacitance; Quantization; Signal resolution; Switched capacitor circuits;
Journal_Title :
Solid-State Circuits, IEEE Journal of
