cx25840 Conexant Systems, Inc., cx25840 Datasheet - Page 19

• Manufacturer Part Number: cx25840
• Description: Video Decoder And Broadcast Audio
• Manufacturer: Conexant Systems, Inc.

2.1
Table 2-1. Pin Descriptions (1 of 4)
102284B
8/3/05
CVBS{1:3}/Y{1:3}
CVBS{4:6}/Y4/C{1:2}/
SIF{1:3}/Pb{1:2}
CVBS{7:8}/C{3:4}/
SIF{4:5}/Pr{1:2}
IREF
VAA_ADC{1:2}
VSS_ADC{1:2}
VAA_CH{1:2}
VSS_CH{1:2}
ASUB
S2D_NEG{1:2}
Pin Name
2
Pin Descriptions
58, 60,
61
63, 65,
67
69, 71
66
53, 56
54, 55
62, 70
64, 72
57
59, 68
Pin
Pin Descriptions
See
I
I
I
I/O
I
I
I
I
I
I
Dir
Table 2-1
As
As
As
Ar
Ap
Ap
Ap
Ap
Ap
Ar
Type
for pin descriptions.
Composite or Luma signal input to ADC1. The signal passes through on-chip
analog multiplexers before passing through a gain stage, an anti-alias filter stage,
and into ADC1. Unused inputs should be left floating.
Chroma, Sound IF, or Pb signal input to ADC2 or Luma, Composite signal input to
ADC1. This signal passes through on-chip analog multiplexers before passing
through a gain stage, an anti-alias filter stage, and into either ADC1 or ADC2. In
color component (Pb, Pr) input mode, the Pb component should be connected to
one of these pins, and the Pr component should be connected to the Pr{1:2} pins.
Unused inputs should be left floating.
Chroma, Sound IF or Pr signal input to ADC2 or Luma, Composite signal input to
ADC1. This signal passes through on-chip analog multiplexers before passing
through a gain stage, an anti-alias filter stage, and into either ADC1 or ADC2. In
color component (Pb, Pr) input mode, the Pr component should be connected to
this pin, and the Pb should be connected to a Pb{1:2} pin. Unused inputs should be
left floating.
Current reference pin. Connect 30 kΩ, 5% precision resistor to ground.
ADC core power, one for each ADC. VAA_ADC = 3.3 V nominal.
ADC core ground, one for each ADC.
Analog channel 1 and 2 (clamp, single-to-diff, VGA, filter) power. VAA_CH = 3.3 V
nominal.
Analog channel 1 and 2 (clamp, single-to-diff, VGA, filter) ground.
ADC core substrate ground.
Negative input of single-to-differential converter. Tie to analog ground through AC
coupling capacitor for common mode noise rejection. The capacitor should match
the value used on the analog inputs.
Conexant
Description: {20} ADC Analog
2-1