Title :
A buffered, constant gain, opamp with rail-to-rail common-mode range
Author :
Moldovan, Laszlo ; Li, Hua
Author_Institution :
Dept. of Comput. Sci., Texas Tech. Univ., Lubbock, TX, USA
Abstract :
A buffered, high frequency, high DC gain, rail-to-rail, constant transconductance (Gm) operational amplifier was designed. The operational amplifier is a part of an analog/digital system which implements a Gabor convolution for real-time dynamic image processing. This op amp is designed to drive the input impedance (50 Ω||35 pF) of an off-chip analog-to-digital converter (ADC). It operates from a single 5 V power supply, offers a 66 dB open loop voltage gain (Avol), and a 9.5 MHz unity gain-bandwidth (GBW) for the above mentioned load. Its uniqueness includes a rail-to-rail input and output voltage swing with a phase margin (PM) of 77° and a DC common mode rejection ratio (CMRR) of 105 dB as well as a power dissipation of 10 mW. The buffer is able to drive the ADC input impedance with a positive and negative slew rate (SR) of 12 V/μs. In addition to rail-to-rail output voltage swing, the op amp has a constant Gm over the whole common mode (CM) voltage range
Keywords :
CMOS analogue integrated circuits; HF amplifiers; buffer circuits; operational amplifiers; radiofrequency amplifiers; 10 mW; 5 V; 66 dB; 9.5 MHz; ADC input impedance driving; DC CMRR; Gabor convolution; buffered constant gain op amp; common mode rejection ratio; constant transconductance; high DC gain; high frequency operation; operational amplifier; rail-to-rail common-mode range; real-time dynamic image processing; single 5 V power supply; Convolution; Digital systems; Frequency; Impedance; Operational amplifiers; Rail to rail amplifiers; Rail to rail operation; Real time systems; Transconductance; Voltage;
Conference_Titel :
Circuits and Systems, 1996. ISCAS '96., Connecting the World., 1996 IEEE International Symposium on
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-3073-0
DOI :
10.1109/ISCAS.1996.539876
