A large-signal very low-distortion transconductor for high-frequency continuous-time filters

• Published in: IEEE journal of solid-state circuits Vol. 26; no. 7; pp. 946 - 955
• Main Authors: Silva-Martinez, J., Steyaert, M.S.J., Sansen, W.M.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.1991; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Bandwidth; Dynamic range; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Filters; Operational amplifiers; Q factor; Total harmonic distortion; Transconductance; Transconductors; Transducers; Voltage; Operational amplifier; Voltage current curve; Q factor; Noise; Biquad circuit; Experimental study; Complementary MOS technology; Frequency response; Passband; High frequency; Signal distortion; Transconductance; Electric filter
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/4.92014

A high-frequency large-signal very low-distortion voltage-to-current transducer is presented. The total harmonic distortion (THD), for supply voltages of only +or-2.5 V, is smaller than 0.1% for fully differential input signals up to 2.4 V peak to peak (V/sub pp/). The dynamic range is on the order of 89 dB with the transconductor noise integrated over a bandwidth of 1 MHz. Moreover, this structure presents low sensitivity to transistor mismatches. An operational transconductance amplifier (OTA), based on this transconductor, has been used in an adjustable quality factor 1.8-MHz biquadratic continuous-time filter. The quality factor Q is controlled, from 2 to 50, with a novel current-source configuration. Both the OTA and the filter have been fabricated in a CMOS 3- mu m n-well process.< >