Electronically tunable low-pass filter in PLL frequency synthesizer

Author

Tsukutani, Takao ; Sumi, Yasuaki ; Higashimura, Masami ; Fukui, Yutaka

Author_Institution

Dept. of Electr. Eng., Matsue Nat. Coll. of Technol., Japan

fYear

2001

fDate

2001

Firstpage

55

Lastpage

59

Abstract

This paper presents a low-pass filter circuit configuration with changeable time constants for a phase locked loop (PLL) frequency synthesizer in multiprogrammable divider (PD) method. The low-pass filter employs operational transconductance amplifiers (OTAs) and grounded capacitor as the basic building units. The time constants can be electronically changed through adjusting the bias currents of OTAs. The PLL frequency synthesizer with the proposed filter has higher speed lock-up time and quality than the conventional one

Keywords

automotive electronics; circuit tuning; frequency synthesizers; low-pass filters; operational amplifiers; phase locked loops; PLL frequency synthesizer; bias currents; changeable time constants; electronically tunable low-pass filter; grounded capacitor; higher speed lock-up time; low-pass filter circuit; multiprogrammable divider method; operational transconductance amplifiers; phase locked loop frequency synthesizer; vehicle electronics; Capacitors; Frequency synthesizers; Information filtering; Information filters; Low pass filters; Phase locked loops; Transconductance; Transfer functions; Tunable circuits and devices; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicle Electronics Conference, 2001. IVEC 2001. Proceedings of the IEEE International

Conference_Location

Tottori

Print_ISBN

0-7803-7229-8

Type

conf

DOI

10.1109/IVEC.2001.961726

Filename

961726