ak4633 AKM Semiconductor, Inc., ak4633 Datasheet - Page 31

• Manufacturer Part Number: ak4633
• Description: 16-bit ?? Mono Codec With Alc & Mic/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
When PMPLL bit is “0” and M/S bit is “0”, the AK4633 becomes EXT slave mode. Master clock is input from MCKI pin,
the internal PLL circuit is not operated. This mode is compatible with I/F of the normal audio CODEC. The clocks
required to operate are MCKI (256fs, 512fs or 1024fs), BICK (≥32fs) and FCK (fs). The master clock (MCKI) should be
synchronized with FCK. The phase between these clocks does not matter. The input frequency of MCKI is selected by
FS3-0 bits ( Table 11).
External Slave Mode does not support Mode 0 (DSP Mode) of Audio Interface Format.
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 AOUT amp at fs=8kHz is shown in Table 12.
The external clocks (MCKI, BICK and FCK) should always be present whenever the ADC or DAC or Programmable
Filter are in operation (PMADC bit = “1” or PMDAC bit = “1” or PMPFIL bit = “1”). If these clocks are not provided, the
AK4633 may draw excess current and it is not possible to operate properly because utilizes dynamic refreshed logic
internally. If the external clocks are not present, the ADC, DAC and Programmable Filter should be in the power-down
mode (PMADC bit =PMDAC bit = PMPFIL bit = “0”).
MS0447-E-03
EXT Slave Mode (PMPLL bit = “0”, M/S bit = “0”)
Mode
0
1
2
3
Table 11. Setting MCKI Frequency at EXT Slave Mode (PMPLL bit = “0”, M/S bit = “0”)
FS3-2 bits
Don’t care
Don’t care
Don’t care
Don’t care
Table 12. Relationship between MCKI and S/N of AOUT
AK4633
1024fs
MCKI
256fs
512fs
FS1 bit
MCKO
MCKI
BICK
FCK
SDTO
SDTI
0
0
1
1
Figure 21. EXT Slave Mode
(fs=8kHz, 20kHzLPF + A-weighted)
FS0 bit
256fs, 512fs or 1024fs
0
1
0
1
32fs, 64fs
- 31 -
1fs
MCKI Input
84dB
92dB
92dB
S/N
Frequency
1024fs
256fs
256fs
512s
MCLK
BCLK
FCK
SDTI
SDTO
DSP or µP
7.35kHz ≤ fs ≤ 48kHz
7.35kHz < fs ≤ 13kHz
7.35kHz < fs ≤ 26kHz
7.35kHz < fs ≤ 48kHz
Sampling Frequency
Range
Default
[AK4633]
2006/04