ak4387 AKM Semiconductor, Inc., ak4387 Datasheet - Page 19

• Manufacturer Part Number: ak4387
• Description: 106db 192khz 24-bit 2ch ?? Dac
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
[AK4387]
1. Grounding and Power Supply Decoupling
AVDD, DVDD and VSS are supplied from analog supply and should be separated from system digital supply.
Decoupling capacitor, especially 0.1µF ceramic capacitor for high frequency should be placed as near to AVDD, DVDD
as possible. The differential Voltage between AVDD and VSS pins set the analog output range.
2. Analog Outputs
The analog outputs are single-ended and centered around the VCOM voltage. The output signal range is typically
2.95Vpp (typ@AVDD=5V). The phase of the analog outputs can be inverted channel independently by INVL/INVR bits.
The internal switched-capacitor filter and continuous-time filter attenuate the noise generated by the delta-sigma
modulator beyond the audio passband. The output voltage is a positive full scale for 7FFFFFH (@24bit) and a negative
full scale for 800000H (@24bit). The ideal output is VCOM voltage for 000000H (@24bit).
DC offsets on analog outputs are eliminated by AC coupling since analog outputs have DC offsets of VCOM + a few mV.
Figure 11 shows an example of the external LPF with 2Vrms output.
390p
3.3k
3.3k
+Vop
Analog
22u
3.0k
3.9k
AOUT
Out
-Vop
22k
470p
fc=108.6kHz, Q=0.706, g=-0.08dB at 40kHz
nd
Figure 11. External 2
order LPF Circuit Example (using op-amp with dual power supplies)
MS0429-E-00
2005/09
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