AK4683_07 Datasheet, PDF (40/84 Pages) Asahi Kasei Microsystems – Asynchronous Multi-Channel Audio CODEC with DIR/T

[AK4683]
■ Input Selector, Input Attenuator
The AK4683 includes 6ch stereo input selectors (Figure 21). The input selector is 6 to 1 selector. The AIN2-0 bits set
the input channel (Table 39).
AIN2 bit
0
0
0
0
1
1
1
1
AIN1 bit
0
0
1
1
0
0
1
1
AIN0 bit
0
1
0
1
0
1
0
1
Input Selector
LIN1 / RIN1
LIN2 / RIN2
LIN3 / RIN3
LIN4 / RIN4
LIN5 / RIN5
LIN6 / RIN6
None
None
Default
Table 39. Input Selector
The input ATTs are constructed by adding the input resistor (Ri) for LIN1-6/RIN1-6 pins and the feedback resistor (Rf)
between LOPIN (ROPIN) pin and LISEL (RISEL) pin (Figure 21). The voltage range of the LISEL(RISEL) pin should
be less than typ. 0.62 x AVDD1 (Vpp). If the input voltage of the input selector exceeds typ. 0.62 x AVDD, the input
voltage of the LISEL(RISEL) pins must be attenuated to typ. 0.62 x AVDD1 (Vpp) by the input ATTs. The Table 40
shows the example of Ri and Rf.
Ri
LIN 1
Ri
LIN 2
Ri
LIN 3
Ri
LIN 4
Ri
LIN 5
Ri
LIN 6
LO P IN
Rf
LIS E L
P re-A m p
To ADC
R i R IN 1
R i _{R IN 2}
R i _{R IN 3}
R i _{R IN 4}
R i _{R IN 5}
R i _{R IN 6}
P re-A m p
To ADC
R O P IN
R IS E L
Rf
Figure 21. Input ATT
Input Range
Ri [kΩ]
Rf [kΩ]
ATT Gain [dB] LISEL/R pin
4Vrms
47
12
−11.86
1.02Vrms
(2.88Vpp)
2Vrms
47
24
−5.84
1.02Vrms
(2.88Vpp)
1Vrms
47
47
0
1Vrms
(2.82Vpp)
Note: Input range of internal ADC is 0.62 x AVDD1 (5V) = 3.1Vpp typ.
Table 40. Input ATT example
MS0427-E-02
- 40 -
2007/04