Premium
Active load with cross‐coupled bulk for high‐gain high‐CMRR nanometer CMOS differential stages
Author(s) -
Ballo Andrea,
Grasso Alfio D.,
Pennisi Salvatore
Publication year - 2019
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.2684
Subject(s) - cmos , common mode rejection ratio , transistor , differential gain , differential (mechanical device) , open loop gain , differential amplifier , amplifier , signal (programming language) , operational amplifier , voltage , electronic engineering , automatic gain control , common mode signal , electrical engineering , computer science , engineering , analog signal , semiconductor , semiconductor laser theory , digital signal processing , programming language , aerospace engineering
Summary Nanometer CMOS technologies are characterized by low intrinsic gain and limited rejection to common‐mode disturbances, issues that analog designers must counteract through nonconventional circuit solutions able to operate under sub–1‐V supply voltages. In this letter, an approach originally proposed as a common‐mode control loop for body‐driven amplifiers is exploited by cross‐connecting the bulk terminals of the active‐load transistors of a source‐coupled pair to sensibly improve its small‐signal performance. A design example in 65‐nm process supplied from 750 mV shows that the presented solution offers both a nominal 20‐dB increase in differential gain and 29‐dB increase in CMRR , as compared with the standard counterpart.