ak4538 AKM Semiconductor, Inc., ak4538 Datasheet - Page 22

• Manufacturer Part Number: ak4538
• Description: 16bit ?? Codec With Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

The S/N of the DAC at low sampling frequencies is worse than at high sampling frequencies due to out-of-band noise.
When the out-of-band noise can be improved by using higher frequency of the master clock. The S/N of the DAC output
through Headphone amp at fs=8kHz is shown in Table 11.
n Master Mode/Slave Mode
The M/S pin selects either master or slave modes. M/S pin = “H” selects master mode and “L” selects slave mode. The
AK4538 outputs MCKO, BICK and LRCK in master mode. The AK4538 outputs only MCKO in slave mode, while BICK
and LRCK must be input separately.
MS0198-E-01
MCKO pin
BICK pin
LRCK pin
Mode
0
1
2
3
Table 11. Relationship between MCLK and S/N of HP-AMP
MCKO pin
BICK pin
LRCK pin
Table 8. MCKO Frequency (EXT Mode, MCKO bit = “1”)
Master Mode
Slave Mode
Table 9. Clock Operation at Master Mode (EXT Mode)
Table 10. Clock Operation at Slave Mode (EXT Mode)
Power up
MCKO bit = “0” : “L”
MCKO bit = “1” : Output
Input
Input
MCLK
1024fs
PS1
256fs
512fs
0
0
1
1
Table 12. Master mode/Slave mode
Power up
MCKO bit = “0” : “L”
MCKO bit = “1” : Output
BF bit = “0” : 64fs Output
BF bit = “1” : 32fs Output
Output
MCKO = Output
MCKO = Output
Master Mode (M/S pin = “H”)
S/N (fs=8kHz, A-weighted)
Slave Mode (M/S pin = “L”)
MCKO
PS0
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0
1
0
1
84dB
88dB
88dB
Power down
Fixed to “L” or “H” externally
Fixed to “L” or “H” externally
LRCK = Output
BICK = Output
BICK / LRCK
LRCK = Input
MCKO
BICK = Input
256fs
128fs
64fs
32fs
Power down
“L”
“L”
“L”
“L”
Default
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