AK4425A Datasheet, PDF (11/27 Pages) Asahi Kasei Microsystems – 192kHz 24-Bit Stereo ΔΣ DAC with 2Vrms Output

[AK4425A]
OPERATION OVERVIEW
■ System Clock
The external clocks required to operate the AK4425A are MCLK, LRCK and BICK. The master clock (MCLK) should be
synchronized with LRCK but the phase is not critical. The MCLK is used to operate the digital interpolation filter and the
delta-sigma modulator. The MCLK is used to operate the digital interpolation filter and the delta-sigma modulator. There
are two methods to set MCLK frequency. In Manual Setting Mode (ACKS = “0”: Register 00H), the sampling speed is set
by DFS0/1 (Table 1). The frequency of MCLK at each sampling speed is set automatically. (Table 2) When the power
applied, the AK4425A is in Auto Setting Mode. In Auto Setting Mode (ACKS = “1”: Default), as MCLK frequency is
detected automatically (Table 3), and the internal master clock becomes the appropriate frequency (Table 4), it is not
necessary to set DFS0/1.
The AK4425A is automatically placed in power saving mode when MCLK, LRCK and BICK stop during normal
operation mode, and the analog output is forced to 0V(typ). When MCLK, LRCK and BICK are input again, the
AK4425A is powered up. After power-up, the AK4425A is in the power-down mode until MCLK, LRCK and BICK are
input.
DFS1 DFS0
Sampling Rate (fs)
0
0
Normal Speed Mode
8kHz~48kHz
0
1
Double Speed Mode
60kHz~96kHz
1
0
Quad Speed Mode
120kHz~192kHz
Table 1. Sampling Speed (Manual Setting Mode)
(default)
DFS1
0
0
0
0
0
1
1
DFS0
Sampling
Speed
0
0 Normal
0
1
Double
1
0
Quad
0
LRCK
(kHz)
fs
32.0
44.1
48.0
88.2
96.0
176.4
192.0
MCLK (MHz)
128fs 192fs 256fs 384fs
-
-
8.1920 12.2880
-
-
11.2896 16.9344
-
-
12.2880 18.4320
11.2896 16.9344 22.5792 33.8688
12.2880 18.4320 24.5760 36.8640
22.5792 33.8688
-
-
24.5760 36.8640
-
-
Table 2. System Clock Example
512fs
16.3840
22.5792
24.5760
-
-
-
-
768fs
24.5760
33.8688
36.8640
-
-
-
-
1152fs
36.8640
-
-
-
-
-
-
BICK
(MHz)
64fs
2.0480
2.8224
3.0720
5.6448
6.1440
11.2896
12.2880
MCLK
Sampling Speed
1152fs
Normal (fs=32kHz only)
512fs
768fs
Normal
256fs
384fs
Double
128fs
192fs
Quad
Table 3. Sampling Speed(Auto Setting Mode: Default)
MS1127-E-01
- 11 -
2011/03