AK4205EN Datasheet, PDF (20/25 Pages) Asahi Kasei Microsystems – Ultra Low Noise and Distortion Headphone Amp with Analog Switch

[AK4205]
1. Grounding and Power Supply Decoupling
The AK4205 requires careful attention to power supply and grounding arrangements. PVDDA, PVDDB,
PVEEA, PVEEB and RVDD are usually supplied from the system’s analog supply, and SWVDD is
supplied from the system’s another analog power supply. RVDD/PVDDA/PVDDB and PVEEA/PVEEB
must be connected to the same analog power supplies each. The RSTN pin should be held “L” when
power supplies are tuning on. The RSTN pin is allowed to be “H” after SWVDD is applied and settled.
In order to avoid the pop noise of SWOUTA and SWOUTB output at power-up/down, refer to “p16.■
Analog Switch Power-up/down Sequence”
RVSS, SWVSS, AVSSA, AVSSB and expose pad of the AK4205 should be connected to the analog
ground plane. System analog ground and digital ground should be wired separately and connected
together as close as possible to where the supplies are brought onto the printed circuit board.
Decoupling capacitors should be as close the power supply pins as possible. Especially, the small value
bypass capacitor is to be closest.
2. Analog Inputs
The headphone amplifier inputs (PINA-NINA pins and PINB-NINB pins) support full-differential format.
The input signal range is nominally typ. 2.83 Vpp, centered around 2.5 V. The analog switch inputs
(SWINA, SWINB, AUXA and AUXB pins) support single-ended format. The input signal range is
nominally typ. 6.0 Vpp, centered around VSS (0 V).
3. Analog Outputs
The headphone output (AMPOUTA and AMPOUTB pins) is single-ended and centered around VSS (0
V). There is no need for AC coupling capacitors. The AMPOUTA and AMPOUTB pins should be
connected to SWINA and SWINB pins with a dumping resistor (Rd) in series. The analog switch output
(SWOUTA and SWOUTB pins) is single-ended and centered around VSS (0 V), and they should be
connected directly to a headphone. There is no need for AC coupling capacitors.
016012367-E-00
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2016/12