CS4297 datasheet(42/46 Pages) CIRRUS

42 / 46 page

DS242F5

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 VRMS 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 VRMS 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 VRMS 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.

CS4297 데이터시트(PDF) 42 Page - Cirrus Logic