TITLE:
A New Design Technique of CMOS Current Feed Back Operational Amplifier (CFOA)
AUTHORS:
Hassan Jassim
KEYWORDS:
Synthesis CFA OTA and CMOS CFOA; Cross Coupled Buffer Stage; High Performance CFOA; Low Input Offset Voltage CFOA; Low Distortion CFOA
JOURNAL NAME:
Circuits and Systems,
Vol.4 No.1,
January
25,
2013
ABSTRACT: A new design technique employing CMOS Current Feedback Operational Amplifier (CFOA) is presented. This design approach applies CFA OTA as input stage cascaded with class AB cross-coupled buffer stage. The performance parameters of CMOS CFOA such as bandwidth, slew rate, settling time are extensively improved compared with conventional CFOA. These parameters are very important in high frequency applications that use CMOS CFOA as an active building block such as A/D converters, and active filters. Also the DC input offset voltage and harmonic distortion (HD) are very low values compared with the conventional CMOS CFOA are obtained. P-Spice simulation results using 0.35 μm MI-ETEC CMOS process parameters shows considerable improvement over existing CMOS CFOA simulated model. Some of the performance parameters for example are DC gain of 67.2 dB, open-loop gain bandwidth product of 104 MHz, slew rate (SR+) of +91.3 V/μS, THD of -67 dB and DC input offset voltage of -0.2 mV.