AK4709 Datasheet, PDF (14/42 Pages) Asahi Kasei Microsystems – Low Power AV SCART Switch

[AK4709]
OPERATION OVERVIEW
1. System Reset and Power-down options
The AK4709 should be reset once by bringing PDN pin = “L” after all power supplies are supplied. The AK4709 has
several operation modes. The PDN pin, AUTO bit, MUTE bit, STBY bit and AMP bit control operation mode as shown
in Table 2and Table 3.
■ System Reset and Full Power-down Mode
The AK4709 should be reset once by bringing PDN pin = “L” after all power supplies are supplied.
PDN pin: Power down pin
L: Full Power-down Mode. Power-down, reset and initializes the control register.
H: Device active.
■ Auto Startup Mode
After the PDN pin is set to “H”, the AK4709 is in the auto startup mode. In this mode, all blocks except for the video
detection circuit are powered down (Low power mode). Once the video detection circuit detects video signal from
TVVIN pin or VCRVIN pin, the AK4709 goes to the stand-by mode automatically and sends “L” pulse via INT pin. The
sources of TVOUTL/R are fixed to VCRINL/R, the sources of VCROUTL/R are fixed to TVINL/R respectively. The
source of DC- restore circuit is VCRVIN pin. To exit the auto startup mode, set the AUTO bit to “0”.
AUTO bit (00H D3): Auto startup bit
0: Auto startup disable. (Manual startup)
1: Auto startup enable. (default)
■ Mute Mode
When the MUTE bit = “1” and AUTO bit= “0”, the audio outputs settle to VSS(0V, typ) and the charge pump circuit is in
power down mode.
MUTE bit (00H D1): Audio output control
0: Normal operation.
1: All audio outputs to GND (default)
■ Standby Mode
When the AUTO bit = MUTE bit = “0” and the STBY bit = “1”, the AK4709 is forced into TV-VCR loop through mode.
In this mode, the sources of TVOUTL/R pins are fixed to VCRINL/R pins; the sources of VCROUTL/R are fixed to
TVINL/R pins respectively. All register values are NOT changed by STBY bit = “1”.
STBY bit (00H D0): Standby bit
0: Normal operation.
1: Standby mode. (default)
MS1319-E-00
- 14 -
2011/07