AK4522_12 Datasheet, PDF (16/19 Pages) Asahi Kasei Microsystems – 20Bit Stereo ΔΣ ADC & DAC

ASAHI KASEI
[AK4522]
4. Analog Outputs
The analog outputs are also single-ended and centered around the VCOM voltage. The input signal range scales with the
supply voltage and nominally 0.58 x VREFH Vpp. The DAC input data format is 2’s complement. The output voltage is
a positive full scale for 7FFFFH(@20bit) and a negative full scale for 80000H(@20bit). The ideal output is VCOM
voltage for 00000H(@20bit). The internal switched-capacitor filter and continuous-time filter remove most of the noise
generated by the delta-sigma modulator of DAC beyond the audio passband.
DC offsets on analog outputs are eliminated by AC coupling since DAC outputs have DC offsets of a few mV. Figure 11
shows the example of external op-amp circuit with 6dB gain. The output signal is inverted by using the circuit in this case.
27u
10k
AOUTL
+
2.9Vpp
Vop
4.7k
BIAS 0.1u
10u ⁺
4.7k
18k
Vop=12V
Vop
-
10u
+
+
NJM5532
Lch Out
5.2Vpp
27k
Rch Op-amp
Optional amp with 6dB gain
Figure 11. External analog circuit example (gain=6dB)
M0020-E-02
- 16 -
2012/01