Title :
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
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;
Conference_Titel :
Solid-State Circuits Conference, 1989. ESSCIRC '89. Proceedings of the 15th European
Conference_Location :
Vienna
Print_ISBN :
3-85403-101-7
DOI :
10.1109/ESSCIRC.1989.5468091
