CS4298 Datasheet, PDF (45/52 Pages) Cirrus Logic – SoundFusion Audio/Modem Codec 97 (AMC 97)

CS4298
8.2 Analog I/O Pins
MIC1 - Analog Mono Source, Input
This analog input is a monophonic source to the analog output mixer. It is intended to be used
as a desktop microphone connection to the audio subsystem. This input is MUX selectable to
the input mixer with the MIC2 input source. The maximum allowable input is 1 V_RMS
(sinusoidal). If the 20 dB internal boost is enabled, the maximum allowable input is
100 mV_RMS (sinusoidal). This input is internally biased at the Vrefout voltage reference and
requires AC coupling to external circuitry. If this input is not used, it should be AC coupled to
analog ground.
MIC2 - Analog Mono Source, Input
This analog input is a monophonic source to the analog output mixer. It is intended to be used
as an alternate microphone connection to the audio subsystem. This input is MUX selectable to
the input mixer with the MIC1 input source. The maximum allowable input is 1 V_RMS
(sinusoidal). If the 20 dB internal boost is enabled, the maximum allowable input is
100 mV_RMS (sinusoidal).This input is internally biased at the Vrefout voltage reference and
requires AC coupling to external circuitry. If this input is not used, it should be AC coupled to
analog ground.
LINE_IN_L and LINE_IN_R- Analog Line Source, Inputs
These inputs form a stereo input pair to the CS4298. The maximum allowable input is
1 V_RMS (sinusoidal). These inputs are internally biased at the Vrefout voltage reference. AC
coupling to external circuitry is required. If these inputs are not used, they should both be
connected to the Vrefout pin or both AC coupled, with separate AC coupling caps, to analog
ground.
CD_L and CD_R - Analog CD Source, Inputs
These inputs form a stereo input pair to the CS4298. It is intended to be used for the Red Book
CD audio connection to the audio subsystem. The maximum allowable input is 1 V_RMS
(sinusoidal). These inputs are internally biased at the Vrefout voltage reference. AC coupling to
external circuitry is required. If these inputs are not used, they should both be connected to the
Vrefout pin or both AC coupled, with separate AC coupling caps, to analog ground.
CD_GND - Analog CD Common Source, Input
This analog input is used to remove common mode noise from Red Book CD audio signals.
The impedance on the input signal path should be one half the impedance on the CD_L and
CD_R input paths. This pin requires AC coupling to external circuitry. If this input is not used,
it should be connected to the Vrefout pin or AC coupled to analog ground.
DS315PP2
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