AK4358_06 Datasheet, PDF (32/36 Pages) Asahi Kasei Microsystems – 192kHz 24-Bit 8ch DAC with DSD Input

ASAHI KASEI
[AK4358]
Digital Ground
System
Controller
Analog Ground
13 SDTI4
14 SDTI1
15 SDTI2
16 SDTI3
17 LRCK
18 I2C
19 CCLK/SCL
20 CDTI/SDA
21 CSN/CAD1
22 DCLK
23 DSDL4
24 DSDR4
AK4358
ROUT1+ 48
ROUT1- 47
LOUT2+ 46
LOUT2- 45
ROUT2+ 44
ROUT2- 43
LOUT3+ 42
LOUT3- 41
ROUT3+ 40
ROUT3- 39
LOUT4+ 38
LOUT4- 37
Figure 26. Ground Layout
AVSS and DVSS must be connected to the same analog ground plane.
1. Grounding and Power Supply Decoupling
AVDD and DVDD are usually supplied from analog supply in system and should be separated from system digital supply.
Alternatively if AVDD and DVDD are supplied separately, the power up sequence is not critical. AVSS and DVSS of the
AK4358 must be connected to analog ground plane. System analog ground and digital ground should be connected
together near to where the supplies are brought onto the printed circuit board. Decoupling capacitor, especially 0.1µF
ceramic capacitor for high frequency should be placed as near to AVDD and DVDD as possible.
2. Voltage Reference
VREFH sets the analog output range. VREFH pin is normally connected to AVDD with a 0.1µF ceramic capacitor. All
signals, especially clocks, should be kept away from the VREFH pin in order to avoid unwanted coupling into the
AK4358.
3. Analog Outputs
The analog outputs are full-differential outputs and 0.5 x VREFH Vpp (typ) centered around the internal common voltage
(about AVDD/2). The differential outputs are summed externally, V_AOUT=(AOUT+)-(AOUT-) between AOUT+ and
AOUT-. If the summing gain is 1, the output range is 5.0Vpp (typ @VREFH=5V). The bias voltage of the external
summing circuit is supplied externally. The input data format is 2’s complement. The output voltage(V_AOUT) is a positive
full scale for 7FFFFF (@24bit) and a negative full scale for 800000H (@24bit). The ideal V_AOUT is 0V for 000000H
(@24bit).
The internal switched-capacitor filter and external low pass filter attenuate the noise generated by the delta-sigma
modulator beyond the audio passband. DC offset on AOUT+/- is eliminated without AC coupling since the analog
outputs are differential.
MS0203-E-01
- 32 -
2006/02