AK4387 Datasheet, PDF (8/21 Pages) Asahi Kasei Microsystems – 106dB 192kHz 24-Bit 2ch ΔΣ DAC

ASAHI KASEI
[AK4387]
OPERATION OVERVIEW
„ System Clock
The external clocks, which are required to operate the AK4387, 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. There are two methods to set MCLK frequency. In Manual Setting Mode (ACKS bit
= “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 2~4). After exiting reset (RSTN pin = “↑”), the AK4387 is in Auto Setting Mode. In Auto
Setting Mode (ACKS bit = “1”: Default), as MCLK frequency is detected automatically (Table 5), and the internal master
clock becomes the appropriate frequency (Table 6), it is not necessary to set DFS0/1.
All external clocks (MCLK, BICK and LRCK) should always be present whenever the AK4387 is in the normal operation
mode (RSTN pin = ”H”). If these clocks are not provided, the AK4387 may draw excess current and may fall into
unpredictable operation. This is because the device utilizes dynamic refreshed logic internally. The AK4387 should be
reset by RSTN pin = “L” after threse clocks are provided. If the external clocks are not present, the AK4387 should be in
the power-down mode (RSTN pin = “L”). After exiting reset at power-up etc., the AK4387 is in the power-down mode
until MCLK and LRCK are input.
DFS1
0
0
1
DFS0
0
1
0
Sampling Rate (fs)
Normal Speed Mode
8kHz~48kHz
Double Speed Mode
60kHz~96kHz
Quad Speed Mode
120kHz~192kHz
Default
Table 1. Sampling Speed (Manual Setting Mode)
LRCK
fs
32.0kHz
44.1kHz
48.0kHz
256fs
8.1920MHz
11.2896MHz
12.2880MHz
384fs
12.2880MHz
16.9344MHz
18.4320MHz
MCLK
512fs
16.3840MHz
22.5792MHz
24.5760MHz
768fs
24.5760MHz
33.8688MHz
36.8640MHz
1152fs
36.8640MHz
N/A
N/A
BICK
64fs
2.0480MHz
2.8224MHz
3.0720MHz
Table 2. System Clock Example (Normal Speed Mode @Manual Setting Mode)
LRCK
fs
88.2kHz
96.0kHz
128fs
11.2896MHz
12.2880MHz
MCLK
192fs
256fs
16.9344MHz 22.5792MHz
18.4320MHz 24.5760MHz
384fs
33.8688MHz
36.8640MHz
BICK
64fs
5.6448MHz
6.1440MHz
Table 3. System Clock Example (Double Speed Mode @Manual Setting Mode)
MS0429-E-00
-8-
2005/09