CS4297 Datasheet, PDF (42/46 Pages) Cirrus Logic – CrystalClear SoundFusion Audio Codec 97

CS4297
CrystalClear™ SoundFusion™ Audio Codec ’97
LINE_OUT_L and LINE_OUT_R - Analog Line Level Outputs
These signals are analog outputs from the stereo output mixer. The full scale output voltage for
output is nominally 1 V_RMS and is internally biased at the Vrefout voltage reference. It is
required to either AC couple these pins to external circuitry or DC couple them to a buffer op-
amp biased at the Vrefout voltage. These pins need a 680 pF NPO capacitor attached to analog
ground.
ALT_LINE_OUT_L and ALT_LINE_OUT_R - Analog Alternate Line Level Outputs
These signals are analog outputs from the stereo output mixer. The full scale output voltage for
each output is nominally 1 V_RMS and is internally biased at the Vrefout voltage reference. It is
required to either AC couple these pins to external circuitry or DC couple them to a buffer op-
amp biased at the Vrefout voltage. These pins need a 680 pF NPO capacitor attached to analog
ground.
MONO_OUT, Analog Mono Line Level Output
This signal is an analog output from the Mono output mixer. This is a left and right channel
mix of the output of the stereo input mixer. The full scale output is nominally 1 V_RMS and is
internally biased at the Vrefout voltage reference. AC coupling to external circuitry is required.
This pin needs a 680 pF NPO capacitor attached to analog ground.
Filter and Reference Pins
REFFLT - Internal Reference Voltage, Input
This is the voltage reference used internal to the part. A 0.1 µF and a 1 µF (must not be larger
than 1 µF) capacitor with short, wide traces must be connected to this pin. No other
connections should be made to this pin.
Vrefout - Voltage Reference, Output
All analog inputs and outputs are centered around Vrefout which is nominally 2.2 Volts. This
pin may be used to level shift external circuitry, however any external loading should be
buffered.
AFLT1 - Left Channel Antialiasing Filter Input
This pin needs a 390 pF NPO capacitor attached to analog ground.
AFLT2 - Right Channel Antialiasing Filter Input
This pin needs a 390 pF NPO capacitor attached to analog ground.
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