THC7984 Datasheet, PDF (27/45 Pages) THine Electronics, Inc. – 10-bit 3-channel Video Signal Digitizer

THC7984_Rev.2.0_E
R1B[4:0] Pre-Amp Bandwidth (Low Pass Filter)
The THC7984 has the internal 5th-order Low Pass Filters as anti-aliasing filter for component video input (YPbPr) , and
it's possible to control cut-off frequency in 24 steps between 6 to 92MHz by setting the register.
The THC7984 also has the internal 2nd-order Low Pass Filters to filter the noise and glitch of PC input (RGB) , and it's
possible to control cut-off frequency in 4 steps (40 MHz/90 MHz/170 MHz/310 MHz) by setting the register.
< Preamp Bandwidth>
Analog Input
Preamp Output (ADC Input)
< Cutoff Frequency >
R1B[4:0]
Dec Binary
0 00000
1 00001
2 00010
3 00011
4 00100
5 00101
6 00110
7 00111
8 01000
9 01001
10 0 1 0 1 0
11 0 1 0 1 1
12 0 1 1 0 0
13 0 1 1 0 1
14 0 1 1 1 0
15 0 1 1 1 1
fc
Note
6MHz
7MHz
8MHz
9MHz
10MHz
11MHz
12MHz
13.5MHz
15MHz
18MHz
21MHz
24MHz
27MHz
30MHz
33MHz
36MHz
5th-order LPF
for Component Video
R1B[4:0]
Dec Binary
16 1 0 0 0 0
17 1 0 0 0 1
18 1 0 0 1 0
19 1 0 0 1 1
20 1 0 1 0 0
21 1 0 1 0 1
22 1 0 1 1 0
23 1 0 1 1 1
24 1 1 0 0 0
25 1 1 0 0 1
26 1 1 0 1 0
27 1 1 0 1 1
28 1 1 1 0 0
29 1 1 1 0 1
30 1 1 1 1 0
31 1 1 1 1 1
fc
39MHz
42MHz
46MHz
52MHz
58MHz
66MHz
78MHz
92MHz
40MHz
90MHz
170MHz
310MHz
Note
5th-order LPF
for Component Video
2nd-order LPF
for PC
Reserved
Reserved
Reserved
Reserved
*Setting example
Component video input: About 0.5 times of the sampling frequency is used as cut-off frequency.
PC input: About 1.5 times of the sampling frequency is used as cutoff frequency.
*When R54[4] is set to 1, it's possible to control the cut-off frequency of a 5th-order lowpass filter
in steps of 1MHz between 25MHzto 39MHz by using register R54 [3:0]. In this case, R1B [4:0] is ignored.
< Cutoff Frequency >
R54[3:0]
fc
Dec Binary
Note
0 0 0 0 0 25MHz
1 0 0 0 1 26MHz
2 0 0 1 0 27MHz
3 0 0 1 1 28MHz
4 0 1 0 0 29MHz
5 0 1 0 1 30MHz
6 0 1 1 0 31MHz
7 0 1 1 1 32MHz
5th-order LPF
8 1 0 0 0 33MHz _{for Component Video}
9 1 0 0 1 34MHz
10 1 0 1 0 34MHz
11 1 0 1 1 35MHz
12 1 1 0 0 36MHz
13 1 1 0 1 37MHz
14 1 1 1 0 38MHz
15 1 1 1 1 39MHz
Copyright©2013 THine Electronics, Inc.
27 / 45
THine Electronics, Inc.