Datasheet

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SB0S294E − DECEMBER 2003 − REVISED SEPTEMBER 2006
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7
A capacitor placed in parallel with the resistor (Figure 1)
creates an additional filter pole that provides additional
stop-band attenuation. With a 200 source impedance, a
67pF ceramic capacitor provides approximately 28dB
attenuation at 27MHz without affecting the pass band.
VIDEO PERFORMANCE
Industry standard video test patterns include:
D Multiburst—packets of different test frequencies to
check for basic frequency response.
D Multipulse—pulses modulated at different
frequencies to test for comprehensive measurement
of amplitude and group delay errors across the video
baseband.
D Chrominance-to-luminence (CCIR17) — tests ampli-
tude, phase and some distortion
D 50Hz, 1/2 black−1/2 white screen test signal—tests
the worst case signal swing required by the amplifier.
Performance on these test signals are shown.
Figure 2 shows the test circuits for Figure 3 through
Figure 13 and Figure 16. (NOTE: 1 and 2 indicate
measurement points corresponding to the waveforms
labeled 1 and 2 in the figures.)
1
2
a. Test circuit for Figures 3−5.
2
d. Test circuit for Figures 7, 12, and 13.
1
c. Test circuits for Figures 10 and 11.
2
1
1
1
2
b. Test circuit for Figures 6, 8, and 16.
220
µ
F
22
µ
F
C
OUT
22
µ
F
NOTE: 1 and 2 indicate measurement points corresponding to the waveforms labeled 1 and 2 in the figures.
SAG
47
µ
F
22
µ
F
Figure 2. Test Circuits Used for Figures 3−13