MC44BC375U Datasheet, PDF (10/16 Pages) Freescale Semiconductor, Inc – PLL Tuned VHF (Channel 3 / 4)Audio / Video Modulator

Table 9. Performance Measurement Test Set-Ups (continued)
Device and Signals Set-Up
Measurement Set-Up
Weighted Video Signal to Noise
Video: 100% White video signal — 1 Vpk-pk. The Video Analyzer measures the ratio between the amplitude of the active area
No audio signal
of the video signal (700 mV) and the noise level in Vrms on a video black level
This is measured using a Demodulator in B/G ^{which is shown below.}
using a CCIR Rec. 567 weighting network, VideoS/N is calculated as 20 x log(700 /N) in dB.
100 KHz to 5.0 MHz band with sound trap
and envelope detection, and a Video
Analyzer.
N
noise level in Vrms
Unweighted Video Signal to Noise
Same as above with CCIR filter disabled. Same as above.
Video Differential Phase
Video: 5 step Grey Scale — 1 V_(pp).
No audio signal
On line CCIR 330, the video analyzer DP measure consists of calculating the
difference of the Chroma phase at the black level and the different chroma
This is measured using a Demodulator in B/G ^{subcarrier phase angles at each step of the greyscale. The largest positive or}
using a CCIR Rec. 567 weighting network, ^{negative difference indicates the distortion.}
100 KHz to 5.0 MHz band with sound trap,
and envelope detection, and a Video
the largest positive or negative difference
DIFF PHASE =
the phase at position 0
* 100%
Analyzer.
The video analyzer method takes the worst step from the first 4 steps.
Video Differential Gain
Video: 5 step Grey Scale — 1 V_(pp).
On line CCIR 330 shown below, the video analyzer DG measure consists of
No audio signal
calculating the difference of the Chroma amplitude at the black level and the
This is measured using a Demodulator in B/G ^{different amplitudes at each step of the greyscale. The largest positive or}
using a CCIR Rec. 567 weighting network, ^{negative difference indicates the distortion.}
100 KHz to 5.0 MHz band with sound trap
and envelope detection, and a Video
Analyzer.
1
3
5
0
2
4
5-step Greyscale with Chroma subcarrier superimposed
(not to scale), line CCIR 330.
the largest positive or negative difference
DIFF GAIN =
the amplitude at position 0
* 100%
The video analyzer method takes the worst step from the first 4 steps.
CCIR line 330 corresponds to FCC line 17 in NTSC/M standard.
MC44BC375U
10
Application Specific Products
Freescale Semiconductor