CS4812
Power Supply
VA - Analog Power
Power: analog supply, +5V.
AGND - Analog Ground
Ground: analog ground.
VD - Digital Power
Power: digital supply, +5V.
DGND - Digital Ground
Ground: digital ground.
Analog Inputs
AINL+/-,AINR+/- - Differential Analog Inputs
Inputs: These pins accept differential analog input signals and are internally biased to the reference
voltage of 2.3 V. The + and - input signals should be 180° out of phase. A single-ended signal may also
be directly applied to either the + or - input with the other input AC coupled to ground through a
capacitor. In general, differential input signals provide better performance. For best audio performance,
a passive anti-aliasing filter is required. The typical connection diagram in Figure 5. shows the
recommended single-ended input circuit. Figure 10 shows the recommended differential input circuit.
Inputs may be externally AC or DC coupled. This permits use of the ADCs for input of audio signals or
for measurement of DC control voltages. By default, an internal high pass filter removes any DC offsets
from both of the ADC inputs. If measurement of DC is required on either of the ADC inputs, then the
internal high pass filter must be disabled. Analog audio input signals that are DC coupled must be
biased at 2.3 V to maintain proper input signal swing. DC control input voltages may range from ground
to Vcc and should be applied to only the + or - input with the other input coupled to ground through a
capacitor.
OVL - ADC Overload Indicator
Output: This pin is asserted if either ADC is clipping. The pin does not latch and de-asserts when
clipping stops.
Analog Outputs
AOUT1+/-, AOUT2+/- - Differential Audio Outputs
Outputs: These pins output differential analog signals which are biased to the internal reference voltage
of approximately 2.3V. The + and - output signals are 180° out of phase resulting in a nominal
differential output voltage of twice the output pin voltage. For best performance, an anti-imaging filter is
required. Figure 12 shows the recommended second and third order Butterworth differential-to-single-
ended output buffer circuits.
Voltage Reference
CMOUT - Common Mode Output
Output: This pin provides an internally generated reference of 2.3V to be used for biasing external
analog circuitry. The load on CMOUT must be DC only, with an impedance of not less than 50 kΩ.
CMFILT+,CMFILT- - Common Mode Filter Connections
Inputs: These pins are connections for external filter components required by the internal common mode
reference circuit. See the typical connection diagram in Figure 5. for details.
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DS291PP3