Title :
Design of a 1-V operational passive sigma-delta modulator
Author :
Sai, Toru ; Sugimoto, Yasuhiro
Author_Institution :
Dept. of Electr., Electron., & Commun. Eng., Chuo Univ., Tokyo, Japan
Abstract :
The 1-V operation of a passive sigma-delta modulator has been realized. The dc voltage in the signal paths in the second-order switched capacitor filter section was set at 0.2 V so that metal-oxide-semiconductor (MOS) switches in the signal paths would have enough gate-to-source voltage to turn on without using a voltage boosting scheme. The input switch was replaced by a passive resistor to avoid floating. By modifying gain coefficients in the feedback and the input paths, the bias voltage of digital-to-analog converter (DAC) can be set to 1 V and 0 V and MOS switches become easily activated. Moreover, the correlated double sampling (CDS) scheme was adopted to suppress the 1/f noise and offset voltage produced at the input of a comparator. Successful operation from 1-V supply voltage was confirmed by circuit simulation using the 0.18-mum complementary MOS (CMOS) process.
Keywords :
1/f noise; CMOS integrated circuits; MIS devices; comparators (circuits); resistors; semiconductor switches; sigma-delta modulation; switched capacitor filters; 1/f noise suppression; comparator; complementary MOS process; correlated double sampling scheme; digital-to-analog converter; gain coefficient; gate-to-source voltage; metal-oxide-semiconductor switch; operational passive sigma-delta modulator; passive resistor; second-order switched capacitor filter; size 0.18 mum; voltage 1 V; voltage boosting scheme; Boosting; Delta-sigma modulation; Digital-analog conversion; Feedback; Filters; MOS capacitors; Resistors; Sampling methods; Switches; Voltage;
Conference_Titel :
Circuit Theory and Design, 2009. ECCTD 2009. European Conference on
Conference_Location :
Antalya
Print_ISBN :
978-1-4244-3896-9
Electronic_ISBN :
978-1-4244-3896-9
DOI :
10.1109/ECCTD.2009.5275088
