AK4205EN Datasheet, PDF (16/25 Pages) Asahi Kasei Microsystems – Ultra Low Noise and Distortion Headphone Amp with Analog Switch

[AK4205]
9.5 Control Sequence
■ Analog Switch Power-up/down Sequence
SWVDD pin
RSTN pin
MUTEN pin
SEL pin
CAPSS pin
Switch State
(1) _>1ms
(2)
>5ms
>2ms
(8)
>1ms
(7)
2.5V
1.4V
OFF
(3)
> 300ms
> 300ms
(6)
> 300ms
(4)
(5)
typ. 220ms
OFF→AUX
AUX
typ. 220ms
AUX→Hi-Fi
Hi-Fi
Hi-Fi→AUX
AUX
OFF
AUXA/B pins 0V
SWINA/B pins 0V
SWOUTA/B pins 0V
Figure 13. Power-Up/Down Sequence
<Power up Sequence>
(1) Power up SWVDD while the RSTN, SEL and MUTEN pins are all “L”.
(2) Set the RSTN pin “L” → “H” after power up SWVDD.
1 ms or more “L” period of the RSTN pin is necessary for a curtain reset of the AK4205.
(3) AUX Signal Output: MUTEN pin “L” → “H”
The analog switch near AUX side will be powered on gradually by setting the MUTEN pin to “H”
after 5 ms from the reset release. Mute release time is determined by a capacitor connected to the
CAPSS pin. For example, it will be 220 ms (typ.) if the capacitor value (Css) is 0.1 μF.
(4) Change to Hi-Fi Mode: SEL pin “L” → “H”
The data path is switched to Hi-Fi by setting the SEL pin = “H” after a lapse of 300 ms or more from
the MUTEN pin = “H”. The SEL pin should be set to “H” after stopping the input of the AUXA/B pins.
The transition time depend on the time constant of a capacitor that is connected to the CAPSS pin.
It will be 220 ms (typ.) if the capacitor value (Css) is 0.1 μF.
Change to AUX Mode: SEL pin “H” → “L”
The data path is switched to AUX by setting the SEL pin = “L”. The SEL pin should be set to “L”
after stopping the SWINA/B pins input. The transition time is determined by a capacitor connected
to the CAPSS pin. For example, it will be 220 ms (typ.) if the capacitor value (Css) is 0.1 μF.
016012367-E-00
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2016/12