A wide variable range VCXO for IC

Author

Lee, Yuji ; Sasaki, Yoshinori ; Otsuka, Hideo ; Sekine, Yoshifumi

Author_Institution

Coll. of Sci. & Technol., Nihon Univ., Funabashi, Japan

fYear

1996

fDate

5-7 Jun 1996

Firstpage

722

Lastpage

727

Abstract

We suggest the use of a Miller capacitor as the variable capacitance circuit of the BJT-VCXO (VCXO using a bipolar junction transistor). When the external MOSFET´s gate-drain capacitance is 10 pF, we show that the BJT-VCXO using this variable capacitance circuit has a wide frequency variation of about 500 ppm. Also, we suggest the use of the MOSFET´s resistance change as the variable capacitance circuit of the CMOS-VCXO (VCXO using a CMOS crystal oscillator). When the external gate-drain capacitance is 30 pF, we show that the CMOS-VCXO using this variable capacitance circuit has a wide frequency variation of over 330 ppm

Keywords

CMOS analogue integrated circuits; capacitance; crystal oscillators; variable-frequency oscillators; voltage-controlled oscillators; 10 pF; 30 pF; BJT-VCXO; CMOS crystal oscillator; MOSFET gate-drain capacitance; Miller capacitor; VCO; bipolar junction transistor; variable capacitance circuit; voltage controlled crystal oscillator; wide variable range VCXO; Bipolar integrated circuits; Bipolar transistor circuits; Capacitance; Capacitors; Diodes; Equivalent circuits; Frequency; MOSFET circuits; Voltage control; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control Symposium, 1996. 50th., Proceedings of the 1996 IEEE International.

Conference_Location

Honolulu, HI

Print_ISBN

0-7803-3309-8

Type

conf

DOI

10.1109/FREQ.1996.560246

Filename

560246