Title :
A precise 90° quadrature OTA-C VCO between 50-130 MHz
Author :
Linares-Barranco, B. ; Serrano-Gotarredona, T. ; Ramos-Martos, J. ; Ceballos-Cáceres, J. ; Mora, J.M. ; Linares-Barranco, A.
Author_Institution :
Inst. de Microelectron. de Sevilla, Spain
Abstract :
We present a VLSI continuous time sinusoidal OTA-C quadrature oscillator fabricated in a standard double-poly 0.8 μm CMOS process. The oscillator is tunable in the frequency range from 50-130 MHz. A symmetric topology assures that the two phases produced by the oscillator present an extremely low phase difference error (less than 2° over the whole frequency range). A novel current mode amplitude control scheme is developed that allows for very small amplitudes. Experimental results are provided.
Keywords :
CMOS integrated circuits; VHF oscillators; VLSI; circuit tuning; continuous time systems; network topology; operational amplifiers; variable-frequency oscillators; voltage-controlled oscillators; 0.8 micron; 50 to 130 MHz; CMOS process; VLSI; circuit tuning; continuous time sinusoidal OTA-C quadrature oscillator; current mode amplitude control scheme; low phase difference error; quadrature OTA-C VCO; symmetric topology; Bridge circuits; Envelope detectors; Frequency measurement; Gain measurement; Impedance measurement; Phase measurement; Signal processing; Soil measurements; Transconductance; Voltage-controlled oscillators;
Conference_Titel :
Circuits and Systems, 2004. ISCAS '04. Proceedings of the 2004 International Symposium on
Print_ISBN :
0-7803-8251-X
DOI :
10.1109/ISCAS.2004.1329060
