AK4648 Datasheet, PDF (113/119 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/SPK-AMP

[AK4648]
(9) Fall down the common voltage of headphone-amp: HPMTN bit = “1” → “0”
The fall time depends on HVDD and the capacitor value connected with the MUTET pin. When HVDD=3.3V
and the capacitor value is 1.0μF±30%, the time constant is τ f = 260ms(max.).
If the power supply is powered-off or headphone-Amp is powered-down before the common voltage goes to
VSS2, the pop noise occurs. It takes twice of τf that the common voltage goes to VSS2.
(10) Power down headphone-amp: PMHPL = PMHPR bits = “1” → “0”
(11) Power down DAC and MIN-Amp: PMDAC = PMMIN bits = “1” → “0”
(12) Disable 5-band Equalizer: FBEQ bit = “1” Æ “0”
(13) Disable the path of “DAC → HP-Amp”: DACH bit = “1” → “0”
MS0625-E-01
- 113 -
2007/06