ASAHI KASEI
[AK4702EQ]
System Reset and Power-down control
The AK4702 should be reset once by bringing PDN = “L” upon power-up. The AK4702 has several power-down modes.
The PDN pin, MUTE bit and STBY bit control them as shown in Table 9 and Table 10.
PDN pin: Power down pin.
“H”: Normal operation
“L”: Device power down.
MUTE bit: Analog Mute bit.
“1”: Mute all analog outputs
“0”: Normal operation
STBY bit : Standby bit.
“1”: Standby mode, DAC is powered down, volume is fixed to 0dB, the analog audio/video paths are
fixed to TV-VCR loop-through.
“0”: Normal operation.
After when the PDN pin is set to “H”, the AK4702 is in standby mode and muted. To exit the mute and enter standby
mode, set the MUTE bit to “0” and the STBY bit to “1”. To use the DAC or change analog switches, set the STBY bit to
“0”. The DAC will power up and the internal timing starts clocking LRCK “↑” after exiting reset and power down states
by MCLK. The AK4702 is in power-down mode until MCLK and LRCK are input.
MUTE
bit
STBY
bit
MCLK,
BICK, LRCK
Analog
outputs
Register
control
Mode
PDN pin
“L”
DAC
Powered
Down
Powered
Down
0
1
Device power-down
*
1
*
1
Not Needed
Not Needed
GND
GND
Not Available
Available
Standby and mute
(default)
“H”
fixed to
TV-VCR
loop-through
Powered
Down
2
Standby
“H”
0
1
Not Needed
Available
3
4
Mute
“H”
“H”
1
0
0
0
Needed
Needed
Active
Active
GND
Available
Available
Normal operation
Active
Table 9. Power-down modes (audio)
TVFB,
TVSB
Mode
PDN pin
STBY bit
*
Video outputs
Hi-z
VCRSB
Internally pulled down by
120kohm(typ) resister
0
Power-down
“L”
Hi-z
Active
(Path is fixed)
1
2
Standby
“H”
“H”
1
0
Active
Active
Active
Active
Normal operation
Active
Table 10. Power-down modes (video)
MS0424-E-00
2005/09
- 20 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
