Infotech Oulu Graduate School

Audio converter design for portable systems

Lecturer: Angelo Nagari, ST-NXP Wireless

Date: Thursday, March 12, 2009
Time: 12:15 - 16:00
Room: KE1139

Cellular handset audio requirements have changed dramatically from the basic requirement of two way voice communication. Now the array of audio uses in a cellular handset is staggering as is the complexity:

• the sources of this audio information are coming from different analog and digital devices within the handset.
• the information is coming in analog, and multiple digital formats.
• the information is being sent to multiple types of analog and digital output devices.

The basic purpose of a cellular handset is for voice communication between the caller and the receiver. However, consumers now use the phone for recording messages, playing games, e-mailing photographs and sending text messages, calculating expenses, taking still pictures and video, playing video clips and movie trailers, listening to MP3 files, listening to FM radio, or watching terrestrial or digital wideband broadcast TV, and storing addresses and phone numbers, with more to come.

Due to this audio converter design for portable systems becomes a new challenge for engineers facing high performance, low consumption and low voltage domain in a very “hostile” environment: the mobile phone.

This course will provide an overview of current audio converters design and devices within the cellular handset, as well as information on the direction of future audio converters architectures within cellular handsets.

The basic theory of converters and Sigma-Delta (ΣΔ) converters are provided. ST-NXP design examples already in most of today’s mobile phones are presented to show practical realization of the concepts illustrated.
Course Outline:

• Introduction
• Application Target
• Environment
• Audio Design
• ADC & DAC with ΣΔ architecture
• Audio Amplifier (AB vs D)
• Future Development
• Conclusions

Speaker’s comment: this course is recommended for graduated students or for students close to end of their study. Good knowledge of basis of electronic is required.

More information & registration (before March 6): juha.kostamovaara(at)ee.oulu.fi