CS4239 Datasheet, PDF (85/98 Pages) Cirrus Logic – CrystalClear™ Portable ISA Audio System

CS4239
CrystalClear^TM Portable ISA Audio System
RAUX2 - Right Auxiliary #2 Input
Nominally 1 V_RMS max analog input for the Right AUX2 channel, centered around VREF. A
programmable gain block provides volume control and is located in I5. Typically used for the
Right channel CDROM input.
CMAUX2 - Common Mode Auxiliary #2 Input
Common mode ground input for the LAUX2 and RAUX2 inputs. Typically connected to the
CDROM ground input to provide common-mode noise rejection. The impedance on this pin
should be one half the impedance on the LAUX2 and RAUX2 inputs.
MIN - Mono Input
Nominally 1 V_RMS max analog input, centered around VREF, that goes through a
programmable gain stage (I26) into both channels of the output mixer. This is a general purpose
mono analog input that is normally used to mix the typical "beeper" signal on most computers
into the audio system.
REFFLT - Reference Filter, Input
Voltage reference used internal to the part. A 0.1 µF and a 1 µF capacitor with short fat traces
must be connected between this pin and AGND. No other connections should be made to this
pin.
Analog Outputs
LOUT - Left Line Level Output
Analog output from the mixer for the left channel. Nominally 1 V_RMS max centered around
VREF. This pin needs a 1000 pF NPO capacitor attached and tied to analog ground.
ROUT - Right Line Level Output
Analog output from the mixer for the Right channel. Nominally 1 V_RMS max centered around
VREF. This pin needs a 1000 pF NPO capacitor attached and tied to analog ground.
FLT3D - 3D Filter
This pin needs a 0.01 µF capacitor attached and tied to analog ground.
FLTO - Filter Output
This pin needs a 1000 pF NPO capacitor attached and tied to FLTI.
FLTI - Filter Input
This pin needs a 1000 pF NPO capacitor attached and tied to FLTO.
VREF - Voltage Reference, Output
All analog inputs and outputs are centered around VREF which is nominally 2.1 Volts. This pin
may be used to level shift external circuitry, although any AC loads should be buffered.
DS253PP2
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