Title :
An analysis and implementation of common mode feedback in high-speed fully differential op-amp
Author :
Chen, Chen ; Ge, KangKang ; HE, Lenian
Author_Institution :
Zhejiang Univ., Hangzhou
Abstract :
A systematic analysis on the common mode (CM) component in fully differential operational amplifier is presented. It is revealed that there are two distinct CM closed loops active in a differential op-amp. After a general analysis on the stability of those two CM loops, a novel common mode feedback (CMFB) is proposed for a high-speed fully differential op-amp with a bandwidth of 350 MHz. CMFB is used for each stage of the op-amp. The chip was designed and implemented by using CSMC 0.5 mum CMOS mixed signal process. The testing results indicate that the high-speed op-amp works well and the CM loops are stable.
Keywords :
CMOS integrated circuits; differential amplifiers; feedback; mixed analogue-digital integrated circuits; network analysis; operational amplifiers; CSMC CMOS mixed signal process; common mode component; common mode feedback; fully differential operational amplifier; high-speed fully differential op-amp; systematic analysis; Bandwidth; CMOS process; Delta modulation; Differential amplifiers; Feedback circuits; Feedback loop; Negative feedback; Operational amplifiers; Stability analysis; Voltage;
Conference_Titel :
ASIC, 2007. ASICON '07. 7th International Conference on
Conference_Location :
Guilin
Print_ISBN :
978-1-4244-1132-0
Electronic_ISBN :
978-1-4244-1132-0
DOI :
10.1109/ICASIC.2007.4415710
