A 0.9mA 95dB ΣΔ Modulator for Digital RF Hearing Aid in 0.35μm CMOS

Author

Chang, Long-Xi ; Li, Day-Uei ; Chung, Chi-Chen ; Shia, Tim-Kuei

Author_Institution

Ind. Technol. Res. Inst., Hsinchu

fYear

2007

fDate

27-30 May 2007

Firstpage

489

Lastpage

492

Abstract

A 0.9mA switch-capacitor (SC) third-order ΣΔ modulator for a digital RF hearing aid using a modified feedback loop-filter is presented. This loop-filter is composed of both feedback and feedforward paths. It has two advantages: reduced signal swings inside the ΣΔ loop and the low current consumption. With careful signal scaling, signal swings inside the loop having a -2dB reference voltage input can be suppressed to less than 95% of the reference voltage. This feature greatly enhances loop stability and current efficiency. The chip was implemented in 0.35μm CMOS process, and it achieves a dynamic range of 95dB with a signal bandwidth of 20kHz

Keywords

σ-δ modulation; CMOS integrated circuits; biomedical electronics; circuit feedback; hearing aids; switched capacitor networks; ΣΔ modulator; 0.35 micron; 0.9 mA; 20 kHz; CMOS process; digital RF hearing aid; feedback paths; feedforward paths; modified feedback loop-filter; signal swings; switch-capacitor third-order modulator; Auditory system; Bandwidth; CMOS process; Digital modulation; Dynamic range; Dynamic voltage scaling; Feedback loop; Radio frequency; Signal processing; Stability;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2007. ISCAS 2007. IEEE International Symposium on

Conference_Location

New Orleans, LA

Print_ISBN

1-4244-0920-9

Electronic_ISBN

1-4244-0921-7

Type

conf

DOI

10.1109/ISCAS.2007.378677

Filename

4252678