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AK4343 Datasheet, PDF (57/98 Pages) Asahi Kasei Microsystems – Stereo DAC with HP/RCV/SPK-AMP | |||
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ASAHI KASEI
[AK4343]
 Headphone Output
Power supply voltage for the Headphone-Amp is supplied from the HVDD pin and centered on the HVDD/2 voltage at
VBAT bit = â0â. The load resistance is 16⦠(min). HPG bit selects the output voltage (see Table 49).
HPG bit
0
1
Output Voltage [Vpp]
0.6 x AVDD
0.91 x AVDD
Table 49. Headphone-Amp Output Voltage
When the HPMTN bit is â0â, the common voltage of Headphone-Amp falls and the outputs (HPL and HPR pins) go to
âLâ (HVSS). When the HPMTN bit is â1â, the common voltage rises to HVDD/2 at VBAT bit = â0â. A capacitor between
the MUTET pin and ground reduces pop noise at power-up. Rise/Fall time constant is in proportional to HVDD voltage
and the capacitor at MUTET pin.
[Example]: A capacitor between the MUTET pin and ground = 1.0µF, HVDD=3.3V:
Rise/fall time constant: Ï = 100ms(typ), 250ms(max)
Time until the common goes to HVSS when HPMTN bit = â1â Ã â0â: 500ms(max)
When PMHPL and PMHPR bits are â0â, the Headphone-Amp is powered-down, and the outputs (HPL and HPR pins) go
to âLâ (HVSS).
PMHPL bit,
PMHPR bit
HPMTN bit
HPL pin,
HPR pin
(1) (2)
(3)
(4)
Figure 52. Power-up/Power-down Timing for Headphone-Amp
(1) Headphone-Amp power-up (PMHPL, PMHPR bit = â1â). The outputs are still HVSS.
(2) Headphone-Amp common voltage rises up (HPMTN bit = â1â). Common voltage of Headphone-Amp is rising.
(3) Headphone-Amp common voltage falls down (HPMTN bit = â0â). Common voltage of Headphone-Amp is falling.
(4) Headphone-Amp power-down (PMHPL, PMHPR bit = â0â). The outputs are HVSS. If the power supply is switched
off or Headphone-Amp is powered-down before the common voltage goes to HVSS, some POP noise occurs.
MS0478-E-01
- 57 -
2006/10
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