AK4691 Datasheet, PDF (52/80 Pages) Asahi Kasei Microsystems – 4ch ADC + 2ch DAC with MIC/HP/SPK-AMP

[AK4691]
■ Stereo Line Output (LOUT/ROUT pins)
When DACL bit is “1”, Lch/Rch signal of DAC is output from the LOUT/ROUT pins which is single-ended. When
DACL bit is “0”, output signal is muted and LOUT/ROUT pins output LVCM voltage. The load impedance is 10kΩ
(min.). LVOL2-0 bits set the gain of stereo line output. The Power supply voltage for LINEOUT-Amp is supplied from
LVDD pin. The output level of LINEOUT is constant regardless of LVDD voltage. When the output voltage of LVDD
pin is low, the distortion of LINEOUT degrades. Stereo LINEOUT has two kinds of power-save mode in order to support
a common connector of LINEIN/OUT.
DACL bit _{LVOL2-0 bits}
DAC
LOUT pin
ROUT pin
Figure 33. Stereo Line Output
LVOL2 bit LVOL1 bit LVOL0 bit
Gain
AVDD voltage LINEOUT
0
0
0
0dB
3.0V
-3.9dBV
0
0
1
+2dB
3.0V
-1.9dBV
0
1
0
+5.9dB
3.0V
+2dBV
0
1
1
+6.5dB
2.8V
+2dBV
1
0
0
+7.1dB
2.6V
+2dBV
1
0
1
1
1
x
N/A
Table 44. Stereo Line Output Volume Setting (x: Don’t care, N/A: Not Available)
(default)
1. LMODE bit = “1” (When Line input and Line output are not used as a common connector.)
When the PMLO bit = LOPS bit = “0”, the stereo line output enters power-down mode and the output is pulled-down to
VSS4 by 100kΩ (typ). When the LOPS bit is “1”, stereo line output enters power-save mode. Pop noise at
power-up/down can be reduced by changing PMLO bit at LOPS bit = “1”. In this case, output signal line should be
pulled-down to VSS4 by 20kΩ after AC coupled as Figure 34. Rise/Fall time is 300ms (max) at C=1μF. When PMLO bit
= “1” and LOPS bit = “0”, stereo line output is in normal operation.
LOPS bit
0
1
PMLO bit
Mode
LOUT/ROUT pins
0
Power-down
Pull-down to VSS4
1
Normal Operation
Normal Operation
0
Power-save
Fall down to VSS4
1
Power-save
Rise up to LVCM
Table 45. Stereo Line Output Mode Select @ LMODE bit = “1”
(default)
LOUT pin
ROUT pin
1μF
220Ω
20kΩ
Figure 34. External Circuit for Stereo Line Output (in case of using Pop Reduction Circuit)
MS0672-E-00
- 52 -
2007/11