Title :
A 110 dB CMRR/PSRR/gain CMOS operational amplifier
Author :
Ivanov, Vadim ; Filanovsky, Igor
Author_Institution :
Texas Instruments Inc., Tucson, AZ, USA
Abstract :
A CMOS operational amplifier with 110 dB CMRR/PSRR/gain is described. High CMRR is achieved using a cascoded input stage with high output impedance tail current source. A lateral PNP transistor and low-threshold voltage MOS transistor are used to create the voltage source stabilizing the drain-source voltage of the input transistors. The common-mode input signal range includes the negative rail voltage. A high stability self-regulated bias PTAT core is used to improve PSRR. The amplifier comprises two gain stages connected via a cascoded current mirror with voltage gain boost. The output class AB stage uses local feedback control of the reference voltages, and has an improved quiescent current vs. supply voltage stability.
Keywords :
CMOS analogue integrated circuits; current mirrors; electric impedance; integrated circuit design; operational amplifiers; 110 dB; CMOS operational amplifier; CMRR; cascoded current mirror; class AB stage; drain-source voltage; high output impedance tail current source; input stage design; lateral PNP transistor; low-threshold voltage MOS transistor; negative rail voltage; power supply rejection ratio; quiescent current; voltage gain boost; voltage source stabilization; CMOS technology; Feedback control; Impedance; MOSFETs; Mirrors; Operational amplifiers; Rails; Stability; Tail; Voltage; CMRR; PSRR; cascoding; gain boost; lateral p-n-p transistors; low-threshold voltage MOS transistor; operational amplifiers;
Conference_Titel :
Circuits and Systems, 2005. ISCAS 2005. IEEE International Symposium on
Print_ISBN :
0-7803-8834-8
DOI :
10.1109/ISCAS.2005.1464899
