DocumentCode
896359
Title
Switched-capacitor FSK modulator and demodulator in CMOS technology
Author
Hosticka, Bedrich J. ; Brockherde, Werner ; Kleine, Ulrich ; Zimmer, Günter
Volume
19
Issue
3
fYear
1984
fDate
6/1/1984 12:00:00 AM
Firstpage
389
Lastpage
396
Abstract
A switched-capacitor FSK modulator/demodulator built in silicon-gate CMOS technology is described. The modulator is based on a programmable harmonic oscillator using two stray-insensitive integrators. The centerpiece of the FSK demodulator is a switched-capacitor voltage-controlled oscillator. A simple post-detection processor restores the digital data. Both circuits have been designed for the 600-baud modem channel with 1500 Hz center frequency and ±200 Hz frequency shifts, but the demodulator operates in the 1200-baud channel as well. Due to dynamic biasing the operational amplifiers feature high slew rate, high voltage gain, and low power for capacitive loads.
Keywords
Demodulators; demodulators; CMOS technology; Circuits; Demodulation; Frequency shift keying; High power amplifiers; Low voltage; Modems; Modulation coding; Operational amplifiers; Voltage-controlled oscillators;
fLanguage
English
Journal_Title
Solid-State Circuits, IEEE Journal of
Publisher
ieee
ISSN
0018-9200
Type
jour
DOI
10.1109/JSSC.1984.1052154
Filename
1052154
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