Title :
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
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;
Conference_Titel :
Vehicle Electronics Conference, 2001. IVEC 2001. Proceedings of the IEEE International
Conference_Location :
Tottori
Print_ISBN :
0-7803-7229-8
DOI :
10.1109/IVEC.2001.961726
