Title :
A 14mW 2.5MS/s 14bit Sigma-Delta Modulator Using Pseudo-Differential Split-Path Cascode Amplifiers
Author :
Cao, Zhiheng ; Song, Tongyu ; Yan, Shouli
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX
Abstract :
Switched-capacitor biased pseudo-differential split-path cascode amplifiers are proposed to achieve high power efficiency and small die area for a 14-bit 2.5MS/s DeltaSigma modulator. Sufficient power supply rejection is maintained through the biasing circuit. A novel signal and reference sampling network eliminates input common-mode voltages and relaxes op-amp linearity requirements, making it possible to use short channel length transistors for speed and power efficiency. A prototype chip is fabricated in a 0.25mum CMOS technology with a core area of 0.27mm2. Experimental results show that 84dB dynamic range is achieved with the 1.25MHz signal bandwidth when clocked at 120MHz. The power dissipation is 14mW at 2.5V including the on-chip voltage reference buffers
Keywords :
CMOS integrated circuits; differential amplifiers; operational amplifiers; reference circuits; sigma-delta modulation; switched capacitor networks; 0.25 micron; 1.25 MHz; 120 MHz; 14 bit; 14 mW; 2.5 V; CMOS technology; on-chip voltage reference buffers; op-amp linearity requirements; operational amplifiers; pseudodifferential split-path cascode amplifiers; reference sampling network; short channel length transistors; sigma-delta modulator; switched-capacitor amplifiers; CMOS technology; Circuits; Delta modulation; Delta-sigma modulation; High power amplifiers; Linearity; Operational amplifiers; Power supplies; Sampling methods; Voltage;
Conference_Titel :
Custom Integrated Circuits Conference, 2006. CICC '06. IEEE
Conference_Location :
San Jose, CA
Print_ISBN :
1-4244-0075-9
Electronic_ISBN :
1-4244-0076-7
DOI :
10.1109/CICC.2006.320961
