ak4569 AKM Semiconductor, Inc., ak4569 Datasheet - Page 14

• Manufacturer Part Number: ak4569
• Description: 20-bit Stereo Codec With Ipga & Hp-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
The external clocks required to operate the AK4569 are MCLK(256fs/384fs/512fs), LRCK(fs) and BICK. The master
clock (MCLK) should be synchronized with sampling clock (LRCK). The phase between these clocks does not matter.
The frequency of MCLK is detected automatically, and the internal master clock becomes the appropriate frequency.
Table 1 shows system clock example.
External clocks (MCLK, BICK and LRCK) are needed to operate ADC or DAC. All external clocks (MCLK, BICK and
LRCK) should always be present whenever the ADC or DAC is in normal operation mode (PMADC bit = “1” or PMDAC
bit = “1”). If these clocks are not provided, the AK4569 may draw excess current and will not operate properly because it
utilizes these clocks for internal dynamic refresh of registers. If the external clocks are not present, AK4569 should be
placed in power-down mode (PDN pin = “L” or PMADC bit = PMDAC bit = “0”). When MCLK is input with AC
coupling, the MCKAC bit should be set to “1”. If MCLK with AC coupling stops, MCKPD bit should be set to “1”.
For low sampling rates, outband noise causes both DR and S/N to degrade. DR and S/N are improved by setting DFS bit
to “1”. Table 2 shows S/N of DAC output for both the HP-amp and MOUT. When the DFS bit is “1”, MCLK needs 512fs.
During normal operation, when the ADC or DAC sampling frequency is changed (PMADC bit = “1” or PMDAC bit =
“1”), the DAC output should be soft-muted or “0” data should be input to avoid pop noise.
MS0292-E-01
System Clock
DFS
0
1
Table 2. Relationship among fs, MCLK frequency and S/N of HP-amp and MOUT
8kHz∼48kHz
8kHz∼24kHz
11.025kHz
22.05kHz
44.1kHz
LRCK
12kHz
16kHz
24kHz
32kHz
48kHz
8kHz
fs
fs
11.2896
256fs/384fs/512fs
2.8224
5.6448
12.288
Table 1. System Clock Example
256fs
2.048
3.072
4.096
6.144
8.192
OPERATION OVERVIEW
MCLK
512fs
MCLK (MHz)
16.9344
4.2336
8.4672
12.288
18.432
384fs
3.072
4.608
6.144
9.216
- 14 -
S/N (fs=8kHz, A-weighted)
HP-amp
11.2896
22.5792
84dB
90dB
5.6448
12.288
16.384
24.576
512fs
4.096
6.144
8.192
BICK (MHz)
MOUT
84dB
88dB
0.7056
1.4112
2.8224
0.512
0.768
1.024
1.536
2.048
3.072
64fs
Default
[AK4569]
2005/07