AK4628A Datasheet, PDF (27/41 Pages) Asahi Kasei Microsystems – High Performance Multi-channel Audio CODEC

ASAHI KASEI
[AK4628A]
„ Reset Function
When RSTN = “0”, ADC and DACs are powered-down but the internal register are not initialized. The analog outputs go
to VCOM voltage, DZF1-2 pins go to “H” and SDTO pin goes to “L”. Because some click noise occurs, the analog output
should muted externally if the click noise influences system application. Figure 15 shows the power-up sequence.
RSTN bit
Internal
RSTN bit
ADC Internal
State
DAC Internal
State
ADC In
(Analog)
ADC Out
(Digital)
DAC In
(Digital)
DAC Out
(Analog)
Clock In
MCLK,LRCK,SCLK
DZF1/DZF2
Normal Operation
4~5/fs (9)
1~2/fs (9)
Digital Block Power-down
516/fs ⁽¹⁾
Init Cycle
Normal Operation
Normal Operation
Digital Block Power-down
GD ⁽²⁾
Normal Operation
GD
(3)
“0”data
“0”data
(2)
GD
(6) (5)
(7)
Don’t care
(6)
4∼5/fs (8)
(4)
GD
Notes:
(1) The analog part of ADC is initialized after exiting the reset state.
(2) Digital output corresponding to analog input and analog output corresponding to digital input have the group delay
(GD).
(3) ADC output is “0” data at the power-down state.
(4) Click noise occurs when the internal RSTN bit becomes “1”. Please mute the digital output externally if the click
noise influences system application.
(5) The analog outputs go to VCOM voltage.
(6) Click noise occurs at 4∼5/fs after RSTN bit becomes “0”, and occurs at 1∼2/fs after RSTN bit becomes “1”. This
noise is output even if “0” data is input.
(7) The external clocks (MCLK, BICK and LRCK) can be stopped in the reset mode. When exiting the reset mode, “1”
should be written to RSTN bit after the external clocks (MCLK, BICK and LRCK) are fed.
(8) DZF pins go to “H” when the RSTN bit becomes “0”, and go to “L” at 6~7/fs after RSTN bit becomes “1”.
(9) There is a delay, 4~5/fs from RSTN bit “0” to the internal RSTN bit “0”.
Figure 15. Reset sequence example
MS0385-E-00
- 27 -
2005/02