CS4812

30

DS291PP3

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 k

Ω.

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.