9.1 Audio Input and Output
The audio input circuitry consists of 2 independent 16-bit high-quality ADC channels:
â– Programmable as either stereo line or 1-mic CVC input
â– 1 input programmable as either microphone or line input, the other as line input only
â– Each channel is independently configurable to be either single-ended or fully differential
â– Each channel has an analogue and digital programmable gain stage, this also aids optimisation of different
microphones
The audio output circuitry consists of a single differential class A-B output stage.
013 Note:
6, 2 CSR8615 QFN is designed for a differential audio output. If a single-ended audio output is required, use an
r 1 external differential to single-ended converter.
9.2 Audio Codec Interface eptembe The main features of the interface are:
y, S â– Stereo line analogue input for voice band and audio band
da â– Single mono microphone analogue input for voice band and audio band
on â– Mono analogue output for voice band and audio band
M ■Support for I²S stereo digital audio bus standard
n - â– Support for PCM interface including PCM master codecs that require an external system clock
om.c Important Note:
m.c To avoid any confusion regarding stereo operation this data sheet with respect to audio input, software and any
m registers, channel 0 or channel A represents the left channel and channel 1 or channel B represents the right
co channel.
ache 9.2.1 Audio Codec Block Diagram
o - ap Mono Audio and Voice Band Input
Tsa LINE_BP
s LINE_BN
High-quality ADC
Digital Codec
Digital Circuitry
16
Input B
for jame LINE/MIC_AP
d LINE/MIC_AN
are Mono Audio and Voice Band Output
Prep SPKR_AN
High-quality ADC
Digital Codec
16
Input A
High-quality DAC
16
SPKR_AP
Low-pass Filter
Figure 9.2: Audio Codec Input and Output Stages
The CSR8615 QFN 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 dual power supply, VDD_AUDIO for the audio circuits and VDD_AUDIO_DRV for the audio driver circuits.
Pre-production Information
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