An automatic calibration technique for the OPAMP and its former stage output offset

Author

Shubao, Guo ; Xiaoyan, Zheng ; Yulin, Qiu

Author_Institution

Inst. of Microelectron., Chinese Acad. of Sci., Beijing

Volume

1

fYear

2005

fDate

24-0 Oct. 2005

Firstpage

656

Lastpage

660

Abstract

An automatic calibration technique is developed to trim the differential OPAMP´s input-referred and its former output stage offset voltages. The offset voltage is reduced by digitally adjusting the resulting offset current at the input and its first output stage. Without using complex circuits, the technique just need a comparator, a simple control logical and a current DAC (I-DAC). The proposed circuits have been designed in a 0.25 mum digital CMOS process. The OPAMP can calibrate a maximum offset of plusmn6 mV. The measured input referred offset voltage is less than 100 muV

Keywords

CMOS digital integrated circuits; current comparators; differential amplifiers; digital-analogue conversion; operational amplifiers; 0.25 micron; automatic calibration technique; comparator; control logical; current DAC; differential OPAMP; digital CMOS process; digital-analog converter; offset current; offset voltage; operational amplifier; Analog-digital conversion; Automatic control; CMOS process; Calibration; Capacitors; Counting circuits; Microelectronics; Signal generators; Switches; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

ASIC, 2005. ASICON 2005. 6th International Conference On

Conference_Location

Shanghai

Print_ISBN

0-7803-9210-8

Type

conf

DOI

10.1109/ICASIC.2005.1611334

Filename

1611334