Abstract
A low total harmonic distortion (THD) programmable gain amplifier (PGA) with dual operational amplifiers (op-amps) for electrocardiogram (ECG) signal acquisition applications is presented. The proposed op-amp comprises the rail-to-rail input stage and class-AB output stage. To solve the transconductance (gm) variation caused by the supply voltage changes in rail-to-rail amplifiers with the traditional DC level-shifting technique, a common-mode-detection-based transconductance linearization scheme is proposed in this paper, associated with a 7-steps resistor-feedback digital gain control from 1 V/V to 12 V/V, which can realize less than 2.7% transconductance variations. The proposed rail-to-rail class-AB PGA is implemented in 0.18-μm CMOS technology with 2.7-V∼5-V power supply voltage and 0.07-mm2 core area. Spice simulation results show that the THD is −110 dB with an input signal of 5 mVpp and the input-referred noise spectrum density is 0.5 μV/Hz at a 10-Hz frequency point, after adopting an 8-kHz chopping. The total power consumption including the bias circuit is 81 μW at 2.7 V.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
