CX25870/871
1.0 Functional Description
Flicker-Free Video Encoder with Ultrascale Technology
1.3 Device Description
Finally, Conexant recommends that any designer utilizing the CX25870 in this
mode circumvent the three capacitors and one inductor found in the DAC
low-pass filters used for standard definition TV outputs. Figure 1-37 illustrates
one method of bypassing the capacitors and inductor. Note that an additional
RCA (or other type) of connector is recommended in this case for the Red. Green,
and Blue VGA Outputs.
Figure 1-37. Filterless DAC Outputs for VGA (RGB)—DAC Output Operation
DAC A
2
VGA R
Output
C8
22 pF
0805
5%
D6
BAT54S
SOT-23
5443R10-0041
AOUT
2
L1
1.8 µH
1210
5%
VAA
3.3 V
CVBS =
Composite
R1
75.0 Ω
0805
5%
C9
C10
270 pF
0805
5%
330 pF
0805
5%
2
DAC B
VGA G
Output
68
DACA
C12
22 pF
0805
5%
D6
BAT54S
SOT-23
5443R10-0041
CX25870/871
DAC B
BOUT
2
In VGA Output Mode
L3
1.8 µH
1210
5%
VAA
3.3 V
Y = Luma
R2
75.0 Ω
0805
5%
C13
C14
270 pF
0805
5%
330 pF
0805
5%
70
DACB
2
DAC B
VGA B
Output
C15
22 pF
0805
5%
D6
BAT54S
SOT-23
5443R10-0041
DAC C
COUT
72
2
DACC
L2
1.8 µH
1210
5%
VAA
3.3 V
C = Chroma
R7
75.0 Ω
0805
5%
C16
C17
270 pF
0805
5%
330 pF
0805
5%
NOTE(S):
Make sure to have only one of the paired outputs plugged in simultaneously.
100381_083
100381B
Conexant
1-87
CONEXANT [ CONEXANT SYSTEMS, INC ]
