AK5730 Datasheet, PDF (29/50 Pages) Asahi Kasei Microsystems – 4-Channel Differential Audio ADC for Line & Mic Inputs

[AK5730]
(B)LINE and Phone Input mode (LIN*1-0 bits = “01”)
The stereo line input is a quasi-differential input, R and L share a common return. Line return, phone return and head unit
ground may be isolated from each other. Combinations of two stereo line inputs, one stereo line and one stereo phone
inputs are possible. Any combination of inputs shown left may be connected in the applications.
Parameter
Stereo Line Input Voltage
Phone Input Voltage
Specification
Remarks
1 - 3V RMS
(depending on customer)
0.1 - 3V RMS
(depending on customer)
Table 11 Specification (LINE and Phone Input mode)
LINE or Phone
R2
R1
AC
R2
Mic
Bias,
CP
IN*P
IN*N
Figure 27. LINE and Phone Input Mode(IN*P/N pins)
For Fault Conditions, refer to Table 12 and Figure 28. The “Pos. and neg. inputs shorted State (R2/(2R1+R2)) * Vbias” is
detected based on SAR Threshold A(THA12-01 bits).
The threshold A is a 12bit straight binary code which the full scale is 11V.
Fault Conditions
Conditions
Positive/Negative input shorted to VBAT
VDC+/- ≥ Vbias + Vth
Positive/Negative input shorted to GND
VDC+/- ≤ Vth
Pos. and neg. inputs shorted
R2/(2R1+R2) * Vbias –Vth ≤ VDC+ ≈
VDC- ≤ R2/(2R1+R2) * Vbias + Vth
Positive input open
Vbias - Vth ≤ VDC+ ≤ Vbias + Vth
Negative input open
VDC+/- ≤ Vth
Note. It is not possible to distinguish “Positive/Negative input shorted to GND” and “Negative input open”.
Note. The “Pos. and neg. inputs shorted” is a condition that occurs when there is no input signal, and DC voltage is not
supplied by the input signal.
Table 12 Fault Conditions (LINE and Phone Input Mode)
LINE or Phone
Vbias
R2
AC
R1
VDC+
VDC-
Mic
Bias,
CP
INM*P
INM*N
Figure 28. LINE and Phone Input Mode (IN*MP/N pins)
Rev 0.8
- 29 -
2013/06