Title :
CMRR frequency response of CMOS operational transconductance amplifiers
Author :
Giustolisi, Gianluca ; Palmisano, Giuseppe ; Palumbo, Gaetano
Author_Institution :
Dipt. Elettrico Elettronico e Sistemistico, Catania Univ., Italy
fDate :
2/1/2000 12:00:00 AM
Abstract :
In this paper an accurate and complete analysis of the CMRR for the most commonly used CMOS OTA´s has been carried out. The analysis provides equations which can profitably be used in the design of high-accuracy integrated amplifiers to be employed in instrumentation circuits. The analysis shows that the CMRR of these circuits is highly affected by two poles which are caused by the zeros of the common-mode gain. By using the Spice simulator and the models of a 1.2-μm CMOS process, we have found that the calculated frequency response of CMRR well fits the simulated curves for input frequencies as high as 100 MHz
Keywords :
CMOS analogue integrated circuits; SPICE; current mirrors; frequency response; instrumentation amplifiers; operational amplifiers; poles and zeros; 1.2 micron; 100 MHz; CMOS OTA; CMOS process models; CMRR frequency response; SPICE simulator; common-mode gain; current mirror; differential amplifiers; frequency domain analysis; high frequency effects; high-accuracy integrated amplifiers; instrument amplifiers; poles; source-coupled pair; zeros; Circuit simulation; Differential amplifiers; Equations; Frequency response; Instruments; Linearity; Operational amplifiers; Performance gain; Poles and zeros; Transconductance;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
