AK4706 Datasheet, PDF (31/53 Pages) Asahi Kasei Microsystems – 2ch 24bit DAC with AV Switch & HD/SD Video Filter

ASAHI KASEI
[AK4706]
CIO VCRC
State of VCRC pin
0
0
Hi-Z (default)
0
1
1
0
Active
Connected to GND
1
1
Connected to GND
Table 17 Red/Chroma Bi-directional Control
„ RGB Video Gain Control (06H: D1-D0)
VVOL1-0 bits set the RGB video gain.
VVOL1
0
0
1
1
VVOL0
0
1
0
1
Gain
Output level (Typ. @Input=0.7Vpp)
+6dB
1.4Vpp (default)
+7.2dB
+8.2dB
1.6Vpp
1.8Vpp
+9.1dB
2.0Vpp
Table 18. RGB video gain control
„ Clamp and DC-restore circuit control (06H: D7-D2, 0AH: D3)
Each CVBS and Y input has the sync tip clamp circuit. The DC-restore circuit has two clamp voltages 0.7V(typ) and
2.2V(typ) to support both RGB and YPbPr signal. They correspond to 0.35V(typ) and 1.1V(typ) at the SCART connector
when matched by 75ohm resistors. The CLAMP1, CLAMP0 and CLAMPB bits select the input circuit for ENCRC pin
(Encoder Red/Chroma), ENCB pin (Encoder Blue), VCRRC pin (VCR Red/Chroma) and VCRB pin (VCR Blue)
respectively. VCLP1-0 bits select the sync source of DC- restore circuit.
CLAMPB
0
0
1
1
CLAMP0
0
1
0
1
VCRRC Input Circuit VCRB Input Circuit VCRG Input Circuit
DC restore (0.7V)
DC restore (0.7V)
DC restore (0.7V)
Biased
DC restore (2.2V)
DC restore (0.7V)
DC restore (2.2V)
DC restore (0.7V)
Sync Tip Clamp (0.7V)
(reserved)
(reserved)
(reserved)
Table 19. DC-restore control for VCR Input
note
for RGB
for Y/C
for YPbPr
default
CLAMPB
0
0
1
1
CLAMP1
0
1
0
1
ENCRC Input Circuit
ENCB Input Circuit
DC restore (0.7V)
DC restore (0.7V)
Biased
DC restore (2.2V)
DC restore (0.7V)
DC restore (2.2V)
(reserved)
(reserved)
Table 20. DC-restore control for Encoder Input
note
for RGB
for Y/C
for YPbPr
default
CLAMP2
0
1
ENCG Input Circuit
DC restore (0.7V)
Sync tip clamp (0.7V)
note
for RGB
for YPbPr
default
Note: When the VTV2-0 bits = “001”, TVG bit =”1” and VCLP2-0 bits = “011”, Sync tip is selected even if the CLAMP2
bit = “0”.
Table 21. DC-restore control for Encoder Green/Y Input
MS0507-E-00
- 31 -
2006/05