ASAHI KASEI [AK4382A]
MS0071-E-02 2002/12
- 9 -
OPERATION OVERVIEW
n System Clock
The external clocks, which are required to operate the AK4382A, 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 = “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 (PDN = “↑”), the AK4382A is in Auto Setting Mode. In Auto Setting Mode
(ACKS = “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 AK4382A is in the normal operation
mode (PDN= ”H”). If these clocks are not provided, the AK4382A may draw excess current because the device utilizes
dynamic refreshed logic internally. The AK4382A should be reset by PDN= “L” after threse clocks are provided. If the
external clocks are not present, the AK4382A should be in the power-down mode (PDN= “L”). After exiting reset at
power-up etc., the AK4382A is in the power-down mode until MCLK and LRCK are input.
DFS1 DFS0 Sampling Rate (fs)
0 0 Normal Speed Mode 8kHz~54kHz Default
0 1 Double Speed Mode 60kHz~108z
1 0 Quad Speed Mode 120kHz~216kHz
Table 1. Sampling Speed (Manual Setting Mode)
LRCK MCLK BICK
fs 256fs 384fs 512fs 768fs 64fs
32.0kHz 8.1920MHz 12.2880MHz 16.3840MHz 24.5760MHz 2.0480MHz
44.1kHz 11.2896MHz 16.9344MHz 22.5792MHz 33.8688MHz 2.8224MHz
48.0kHz 12.2880MHz 18.4320MHz 24.5760MHz 36.8640MHz 3.0720MHz
Table 2. System Clock Example (Normal Speed Mode @Manual Setting Mode)
LRCK MCLK BICK
fs 128fs 192fs 256fs 384fs 64fs
88.2kHz 11.2896MHz 16.9344MHz 22.5792MHz 33.8688MHz 5.6448MHz
96.0kHz 12.2880MHz 18.4320MHz 24.5760MHz 36.8640MHz 6.1440MHz
Table 3. System Clock Example (Double Speed Mode @Manual Setting Mode)
LRCK MCLK BICK
fs 128fs 192fs 64fs
176.4kHz 22.5792MHz 33.8688MHz 11.2896MHz
192.0kHz 24.5760MHz 36.8640MHz 12.2880MHz
Table 4. System Clock Example (Quad Speed Mode @Manual Setting Mode)