AK4685 AKM [Asahi Kasei Microsystems], AK4685 Datasheet - Page 22

• Manufacturer Part Number: AK4685
• Description: Multi-channel CODEC with Differential Analog I/O
• Manufacturer: AKM [Asahi Kasei Microsystems]

■
The integrated ADC has a digital high pass filter for DC offset cancelling. The cut-off frequency is 1.0Hz at fs=48kHz
and scales with sampling rate (fs).
■
Each PORTA/B/C can select independent audio interface format. DIFA1-0 bits control the PORTA. The MSB pin and
DIFB bit control PORTB. In all modes, the serial data is MSB first, 2’s complement format. The SDTOB1/2 pins are
clocked out on the falling edge of BICKB pin and the SDTIA/C pins are latched on the rising edge of BICKA/C pins. “0”
should be written to LSB bits without data on each SDTIA/C input.
MS1106-E-00
1. PORTA/C Setting
2. PORTB Setting
2-1: Normal mode:
ADC Digital High Pass Filter
Audio Serial Interface Format
Mode
Mode
The DIFA1-0 bits and DIFC1-0 bits select following four serial data formats
MSB pin and DIFB bit select following four serial data formats
0
1
2
3
0
1
2
3
(DIFC1)
DIFA1
MSB
bit
0
0
1
1
pin
H
H
L
L
(DIFC0)
DIFA0
DIFB
bit
bit
0
0
1
1
0
1
0
1
20bit, Right justified
24bit, Right justified
24bit, Left justified
24bit, Left justified
Table 11. Audio Interface Format
Table 12. Audio Interface Format
24bit, Left justified
SDTOB1,2
24bit, I
24bit, I
24bit, I
SDTIA1
2
2
2
S
S
S
- 22 -
(Table
H/L
H/L
H/L
L/H
H/L
L/H
H/L
L/H
L/R
L/R
LRCKA
LRCKA
12).
(Table
I/O
I/O
O
O
I
I
I
I
I
I
11).
≥ 48fs
≥ 48fs
≥ 48fs
≥ 48fs
≥ 48fs
≥ 48fs
speed
speed
64fs
64fs
BICKA
BICKA
I/O
I/O
O
O
I
I
I
I
I
I
(default)
(default)
(default)
[AK4685]
2009/08