BC352239A Datasheet, PDF (72/116 Pages) List of Unclassifed Manufacturers – BlueCore 3-Multimedia External

Device Terminal Descriptions
8.8 Stereo Audio Interface
The main features of the interface are:
! Stereo and mono analogue input for voice band and audio band
! Stereo and mono analogue output for voice band and audio band
! Support for stereo digital audio bus standards such as I²S
! Support for IEC-60958 standard stereo digital audio bus standards i.e. S/PDIF and AES3/EBU
! Support for PCM interfaces including PCM master CODECs that require an external system clock
AUDIO_IN_P_LEFT
AUDIO_IN_N_LEFT
Input
Amplifier
Σ∆−ADC
AUDIO_OUT_P_LEFT
AUDIO_OUT_N_LEFT
Output
Amplifier
LP Filter
AUDIO_IN_P_RIGHT
AUDIO_IN_N_RIGHT
Input
Amplifier
Σ∆−ADC
DAC
Digital
Circuitry
AUDIO_OUT_P_RIGHT
AUDIO_OUT_N_RIGHT
Output
Amplifier
LP Filter
DAC
Figure 8.28: Stereo CODEC Audio Input and Output Stages
The stereo audio CODEC uses a fully differential architecture in the analogue signal path, which results in low
noise sensitivity and good power supply rejection while effectively doubling the signal amplitude. It operates from
a single power-supply of 1.8V and uses a minimum of external components.
Important Notes:
To avoid any confusion with respect to stereo operation this data sheet explicitly states which is the left and
right channel for audio input and output. With respect to software and any registers, channel 0 or channel A
represents the left channel and channel 1 or channel B represents the right channel for both input and
output.
For mono operation this data sheet uses the left channel for standard mono operation for audio input and
output and with respect to software and any registers, channel 0 or channel A represents the standard mono
channel for audio input and output. In mono operation the second channel which is the right channel,
channel 1 or channel B could be used as a second mono channel if required and this channel will be known
as the auxilliary mono channel for audio input and output.
BC352239A-ds-001Pc
© Cambridge Silicon Radio Limited 2004
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