ak4555 AKM Semiconductor, Inc., ak4555 Datasheet - Page 10

• Manufacturer Part Number: ak4555
• Description: Low Power & Small Package 20bit ?? Codec
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
Data is shifted in/out the SDTI/SDTO pins using SCLK and LRCK inputs. The data is MSB first, 2’s compliment. The
following formats are also valid when SCLK is 64fs: 16-bit data followed by four zeros and 18-bit data followed by two
zeros.
The DAC of AK4555 includes the digital de-emphasis filter (tc=50/15µs) by IIR filter. This filter corresponds to three
frequencies (32kHz, 44.1kHz and 48kHz). The de-emphasis filter selected by DEM0 and DEM1 pins is enabled for input
audio data. The de-emphasis is also disabled at DEM1 pin = “L” and DEM0 pin = “H”.
The AK4555 has a Digital High Pass Filter (HPF) for DC-offset cancel. The cut-off frequency of the HPF is 3.4Hz at
fs=44.1kHz and the frequency response at 20Hz is −0.12dB. It also scales with the sampling frequency (fs).
MS0363-E-01
LRCK
SCLK(64fs
SDTO(o)
SDTI(i)
SDTI(i)
SDTI(i)
SCLK(32fs)
SDTO(o)
SDTI(i)
Audio Serial Interface Format
De-emphasis filter
Digital High Pass Filter
16bit
18bit
20bit
0
0
0
0
1
1
19
15
17
19
15 14
15
2
2
18
14
16
18
14
3
3
16
8
4
0
2
4
8
8
17
9
DEM1 pin
3
1
3
7
7
18
10
Lch Data
H
H
L
L
Table 3. De-emphasis filter control
2
0
2
6
6
Figure 4. Audio Interface Timing
19
11
1
1
5
5
20
12
0
0
4
4
21
13
DEM0 pin
3
3
Don’t Care
Don’t Care
Don’t Care
30
14
- 10 -
H
H
L
L
2
2
31
15
1
1
0
0
0
0
1
1
15 14
15 14
19 18
15
17
19
44.1kHz
48kHz
32kHz
Mode
2
2
OFF
14
16
18
3
3
16
8
4
0
2
8
8
4
17
9
3
1
3
7
7
18
10
Rch Data
0
2
2
6
6
19
11
1
1
5
5
20
12
0
0
4
4
21
13
3
3
Don’t Care
Don’t Care
Don’t Care
30
14
2
2
31
15
[AK4555]
1
1
2005/08
0
0
0
0
1
1