A 3μm-CMOS Analogue Audio Circuit for Mobile Telephone Application

Author

Melcher, Gebhard ; Guerrero, Francisco ; Bärnthaler, Hannes ; Ilzer, Karl ; Strle, Drago ; Groenroos, Mika

Author_Institution

Austria Mikro Syst. Int. GmbH, Unterpremstaetten, Austria

fYear

1989

fDate

20-22 Sept. 1989

Firstpage

204

Lastpage

207

Abstract

An analogue IC for mobile telephone application (Handset IC) is presented. The circuit performs the analogue functions required for the speech channels (low noise microphone amplifier, earphone driver for 130 nF load, sidetone buffer, transmit line driver, speaker line drivers, variable gain-loss stage) and DTMF generation. A buzzer driver has also been integrated for general purpose system signalling. A watchdog circuit supervises the correct functioning of the microprocessor. Common time-continuous and switch-capacitor techniques have been used to minimize the number of external components.

Keywords

CMOS analogue integrated circuits; earphones; low noise amplifiers; microphones; microprocessor chips; mobile handsets; switched capacitor networks; CMOS analogue audio circuit; DTMF generation; analogue functions; analogue integrated circuit; buzzer driver; capacitance 130 nF; earphone driver; handset IC; low noise microphone amplifier; microprocessor; mobile telephone; sidetone buffer; size 3 mum; speaker line drivers; speech channels; switch-capacitor; transmit line driver; variable gain-loss stage; watchdog circuit; Analog integrated circuits; Application specific integrated circuits; Driver circuits; Integrated circuit noise; Low-noise amplifiers; Microphones; Noise generators; Speech enhancement; Telephone sets; Telephony;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference, 1989. ESSCIRC '89. Proceedings of the 15th European

Conference_Location

Vienna

Print_ISBN

3-85403-101-7

Type

conf

DOI

10.1109/ESSCIRC.1989.5468091

Filename

5468091