AK4705 Datasheet, PDF (19/50 Pages) Asahi Kasei Microsystems – 2ch 24bit DAC with AV SCART Switch

[AK4705]
■ Full Power-down Mode
The AK4705 should be reset once by bringing PDN pin = “L” upon power-up.
PDN pin: Power down pin
“H”: Normal operation
“L”: Device power down.
■ Auto Startup Mode
After when the PDN pin is set to “H”, the AK4705 is in the auto startup mode. In this mode, all blocks except for the video
detection circuit are powered down. Once the video detection circuit detects video signal from TVVIN pin or VCRVIN
pin, the AK4705 goes to the stand-by mode (Both Fast Blanking and Slow Blanking are also fixed to VCR-TV
Loop-through) automatically and sends “H” pulse via INT pin. To exit the auto startup mode, set the AUTO bit to “0”.
AUTO bit (00H D3): Auto startup bit
“1”: Auto startup enable (default).
“0”: Auto startup disable (Manual startup).
■ DAC Power-down Mode
The internal DAC block can be powered-down and switched to 1Vrms analog input mode. When DAPD bit =“1”, the
zero-cross detection and offset calibration does not work.
DAPD bit (00H D2): DAC power-down bit.
“1”: DAC power-down. Analog-input mode.
#39 pin: MCLK -> (NC)
#40 pin: BICK -> DACR. Rch analog input.
#41 pin: SDTI -> (NC)
#42 pin: LRCK -> DACL. Lch analog input.
“0”: DAC operation. (default)
■ Standby Mode
When the AUTO bit = MUTE bit = “0” and the STBY bit = “1”, the AK4705 is forced into TV-VCR loop through mode.
In this mode, the sources of TVOUTL/R and MONOOUT pins are fixed to VCRINL/R pins; the sources of VCROUTL/R
are fixed to TVINL/R pins respectively. The gain of volume#1 is fixed to 0dB. All register values themselves are NOT
changed by STBY bit = “1”.
STBY bit (00H D0): Standby bit.
“1”: Standby mode. (default)
“0”: Normal operation.
„ Mute Mode (Bias-off Mode. 00H: D1)
When the MUTE bit = “1”, the bias voltage on the audio output goes to GND level. Bringing MUTE bit to “0” changes
this bias voltage smoothly from GND to VP/2 by 2sec(typ.). This removes the huge click noise related the sudden change
of bias voltage at power-on. The change of MUTE bit from “1” to “0” also makes smooth transient from VP/2 to GND by
2sec(typ). This removes the huge click noise related the sudden change of bias voltage at power-off.
MUTE bit: Bias-off bit.
“1”: Set the audio bias to GND. (default)
“0”: Normal operation
MS0451-E-01
- 19 -
2007/06