Cirrus Logic CS4297A - Manual (Page 43)

CS4297A
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VIDEO_L, VIDEO_R - Analog Video Audio Source, Inputs, Pins 16 and 17
These inputs form a stereo input pair to the CS4297A. It is intended to be used for the audio signal
output of a video device. The maximum allowable input is 1 V
RMS
(sinusoidal). These inputs are
internally biased at the Vrefout voltage reference and require AC-coupling to external circuitry. 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.
AUX_L, AUX_R - Analog Auxiliary Source, Inputs, Pins 14 and 15
These inputs form a stereo input pair to the CS4297A. The maximum allowable input is 1 V
RMS
(sinusoidal). These inputs are internally biased at the Vrefout voltage reference and require AC-coupling
to external circuitry. 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.
LINE_OUT_L, LINE_OUT_R - Analog Line-Level, Outputs, Pins 35 and 36
These signals are analog outputs from the stereo output mixer. The full-scale output voltage for each
output is nominally 1 V
RMS
(sinusoidal). These outputs are internally biased at the Vrefout voltage
reference and require either AC-coupling to external circuitry or DC-coupling to a buffer op-amp biased
at the Vrefout voltage. These pins need a 680-1000 pF NPO capacitor attached to analog ground.
ALT_LINE_OUT_L, ALT _LINE_OUT_R - Analog Alternate Line-Level, Outputs, Pins 39 and 41
These signals are analog outputs from the stereo output mixer. The full-scale output voltage for each
output is nominally 1 V
RMS
(sinusoidal). These outputs are internally biased at the Vrefout voltage
reference and require either AC-coupling to external circuitry or DC-coupling to a buffer op-amp biased
at the Vrefout voltage. These pins need a 680-1000 pF NPO capacitor attached to analog ground.
MONO_OUT - Analog Mono Line-Level, Output, Pin 37
This signal is an analog output from the stereo-to-mono mixer or MIC1/2. The full-scale output voltage
for this output is nominally 1 V
RMS
(sinusoidal). This output is internally biased at the Vrefout voltage
reference and requires either AC-coupling to external circuitry or DC-coupling to a buffer op-amp biased
at the Vrefout voltage. This pin needs a 680-1000 pF NPO capacitor attached to analog ground.
Clock and Configuration
XTL_IN - Crystal Input/Clock Input, Pin 2
In primary mode this pin requires either a 24.576 MHz crystal, with the other pin attached to XTL_OUT,
or an external CMOS clock. The crystal frequency must be 24.576 MHz and designed for fundamental
mode, parallel resonance operation. If an external CMOS clock is used to drive this pin, it must run at
24.576 MHz. In secondary mode all timing is derived from the BIT_CLK input signal and this pin should
be left floating.
XTL_OUT - Crystal Output, Pin 3
This pin is used when a crystal is placed between XTL_OUT and XLT_IN. If an external 24.576 MHz
clock is used on XTL_IN, this pin must be left floating with no traces or components connected to it. In
secondary mode this pin should be left floating.
ID1#, ID0# - Codec ID, Inputs, Pins 45 and 46
These pins select the Codec ID and mode of operation for the CS4297A. They are only sampled after
the rising edge of RESET#. These pins are internally pulled up to the digital supply voltage and should
be left floating for logic ‘0’ or tied to digital ground for logic ‘1’. When both pins are left floating the
CS4297A is the primary codec. If either or both pins are tied to ground the CS4297A is a secondary
codec.
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CS4297A