AK4205EN Datasheet, PDF (18/25 Pages) Asahi Kasei Microsystems – Ultra Low Noise and Distortion Headphone Amp with Analog Switch

[AK4205]
■ Hi-Fi Mode ⇔ AUX Mode Pop Noiseless Change Sequence
SWVDD pin
RSTN pin
>1ms
(1)
MUTEN pin
>5ms
RVDD,
70%
PVDDA/B
0V
0V
PVEEA/B
DAC
Power-up
Power-down
SEL pin
2.5V
CAPSS pin
1.4V
Switch State
> 0ms
> 0ms
(2)
*1
(3)
(4)
*1: DAC Power-up Time
*2: DAC Power-down Time
> 300ms
(5)
AUX
typ. 220ms
AUX→Hi-Fi
Hi-Fi
(8)
*2
(7)
> 300ms
(6)
typ. 220ms
Hi-Fi→AUX
AUX
AUXA/B pins ^0V
SWINA/B pins ^0V
DAC Mute
or
No Signal Input
SWOUTA/B pins ^0V
Figure 14. Hi-Fi ⇔ AUX Path Switching Sequence
<Sequence>
(1) At first, set up analog switch according to the its power-up/down sequence (Refer to “p16.■ Analog
Switch Power-up/down Sequence (1)~(3)”).
Changing AUX Mode ⇒ Hi-Fi Mode
(2) When the AUX input is 0V, power up headphone-amp power supplies (RVDD, PVDDA/B, PVEEA/B).
After RVDD and PVDDA/B are powered up, power up PVEEA/B. (Refer to “p11.■ Headphone-amp
Power-up/down Timing”)
(3) When the headphone-amp is powered up, power up the power supply of DAC connected near Hi-Fi
side.
(4) After DAC output is Enabled: SEL pin “L” → “H”
Do not input signal to the SWINA/B pins in the middle of transition.
(5) DAC signal starts being output.
Changing Hi-Fi Mode ⇒ AUX Mode
(6) Set the SEL pin “H” → “L” after stopping DAC output.
Set the SEL pin to “L” after the DAC is muted or data input is stopped.
(7) Power-up the DAC with an interval of 300ms or more after setting the SEL pin to “L”.
(8) Turn off the headphone amplifier power supplies (PVEEA/B, RVDD, PVDDA/B) after power downing
the DAC. PVEEA/B must be powered down before RVDD and PVDDA/B. (Refer to “p11.■
Headphone-amp Power-up/down Timing”)
016012367-E-00
- 18 -
2016/12