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
18k
Vop
AOUTL
2.9Vpp
Vop=12V
+
Vop
4.7k
10u
+
Lch Out
5.2Vpp
-
+
BIAS 0.1u
NJM5532
27k
+
10u
4.7k
Rch Op-amp
Optional amp with 6dB gain
Figure 11. External analog circuit example (gain=6dB)
M0020-E-02
2012/01
- 16 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
