Title :
A low-power NMOS transmit/receive IC filter for PCM telephony
Abstract :
A very low-power single chip NMOS implementation of the transmit and receive PCM filters used in telephony applications is described. The circuit utilizes doubly-terminated switched capacitor low-pass and high-pass filters and meets accepted requirements without trimming. The filters have low idle-channel noise, consume only 20 mW of power, and are realized in a small area of silicon. Design of the overall architecture, the individual filter sections, and the operational amplifiers in NMOS technology is described.
Keywords :
Active filters; Digital communication systems; Field effect integrated circuits; High-pass filters; Low-pass filters; Pulse-code modulation; Switched capacitor networks; Switched filters; Telephone equipment; active filters; digital communication systems; field effect integrated circuits; high-pass filters; low-pass filters; pulse-code modulation; switched capacitor networks; switched filters; telephone equipment; Active filters; Circuits; Codecs; Costs; MOS devices; Phase change materials; Silicon; Switches; Switching systems; Telephony;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.1980.1051509
