Title :
A precise 90° quadrature OTA-C oscillator tunable in the 50-130-MHz range
Author :
Linares-Barranco, Bernabé ; Serrano-Gotarredona, Teresa ; Ramos-Martos, Juan ; Ceballos-Cáceres, Joaquín ; Mora, José Miguel ; Linares-Barranco, Alejandro
Author_Institution :
Inst. de Microelectron. de Sevilla, Seville, Spain
fDate :
4/1/2004 12:00:00 AM
Abstract :
We present a very-large-scale integration continuous-time sinusoidal operational transconductance amplifiers quadrature oscillator fabricated in a standard double-poly 0.8-μm CMOS process. The oscillator is tunable in the frequency range from 50 to 130 MHz. The two phases produced by the oscillator show a low-quadrature phase error. A novel current-mode amplitude control scheme is developed that allows for very small amplitudes. Stability of the amplitude control loop is studied as well as design considerations for its optimization. Experimental results are provided.
Keywords :
VLSI; operational amplifiers; optimisation; oscillators; phase noise; quadrature amplitude modulation; 50 to 130 MHz; VLSI; analog very large-scale integration; continuous-time sinusoidal operational transconductance amplifiers quadrature oscillator; current-mode amplitude control; gmC; impedance probe; low-quadrature phase error; multiphase oscillators; oscillator stability; phase noise; quadrature OTA-C oscillator tunable; quadrature oscillators; sinusoidal oscillators; standard double-poly; transconductance-capacitance oscillators; very-large-scale integration; Bridge circuits; Frequency; Impedance measurement; Operational amplifiers; Oscillators; Probes; Soil; Transconductance; Tunable circuits and devices; Very large scale integration;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2004.823673
