ak4527b AKM Semiconductor, Inc., ak4527b Datasheet - Page 15

• Manufacturer Part Number: ak4527b
• Description: High Performance Multi-channel Audio Codec
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
n De-emphasis Filter
The AK4527B includes the digital de-emphasis filter (tc=50/15µs) by IIR filter. This filter corresponds to three sampling
frequencies (32kHz, 44.1kHz, 48kHz). De-emphasis of each DAC can be set individually by register data of DEMA1-C0
(DAC1: DEMA1-0, DAC2: DEMB1-0, DAC3: DEMC1-0, see “Register Definitions”).
n Digital High Pass Filter
The ADC has a digital high pass filter for DC offset cancel. The cut-off frequency of the HPF is 0.9Hz at fs=44.1kHz and
also scales with sampling rate (fs).
n Audio Serial Interface Format
Four serial data modes can be selected by the DIF0 and DIF1 pins (P/S = “H”) or bits (P/S = “L”) as shown in Table 7. In
all modes the serial data is MSB-first, 2’s compliment format. The SDTO is clocked out on the falling edge of BICK and
the SDTI/DAUX are latched on the rising edge of BICK.
Figures 1 4 shows the timing at SDOS = “L”. In this case, the SDTO outputs the ADC output data. When SDOS = “H”,
the data input to DAUX is converted to SDTO’s format and output from SDTO. Mode 2 and mode 3 in SDTI/DAUX
input formats can be used for 16-20bit data by zeroing the unused LSBs.
MS0056-E-00
Mode
0
1
2
3
Mode
DIF1
0
1
2
3
4
5
6
7
0
0
1
1
DIF0
32.0kHz
44.1kHz
48.0kHz
88.2kHz
96.0kHz
0
1
0
1
LRCK
Sampling Speed
Table 5. System Clock Example (Auto Setting Mode)
Normal Speed
Normal Speed
Normal Speed
Normal Speed
Double Speed
Double Speed
Double Speed
Double Speed
fs
24bit, MSB justified
24bit, MSB justified
24bit, MSB justified
24bit, IIS (I2S)
Table 6. De-emphasis control
22.5792
24.5760
Table 7. Audio data formats
SDTO
256fs
-
-
-
MCLK (MHz)
DEM1
- 15 -
0
0
1
1
0
0
1
1
16.3840
22.5792
24.5760
512fs
20bit, LSB justified
24bit, LSB justified
24bit, MSB justified
24bit, IIS (I2S)
-
-
SDTI1-3, DAUX
DEM0
0
1
0
1
0
1
0
1
Sampling
Normal
Double
Speed
44.1kHz
48kHz
32kHz
DEM
OFF
OFF
OFF
OFF
OFF
LRCK
H/L
H/L
H/L
L/H
Default
Default
[AK4527B]
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