MC44BC375U Datasheet, PDF (8/16 Pages) Freescale Semiconductor, Inc – PLL Tuned VHF (Channel 3 / 4)Audio / Video Modulator

CHARACTERIZATION MEASUREMENT CONDITIONS
Device default configuration unless otherwise specified:
• Sound subcarrier frequency = 5.5 MHz
• Picture-to-sound carrier ratio = 14 dB
• CH3 and CH4 frequencies
• RF Inputs / Output into 75 Ω Load using a 75 to 50 Ω
transformation
• Video Input 1.0 V pk-pk
• Audio pre-emphasis circuit engaged
Table 9. Performance Measurement Test Set-Ups
Device and Signals Set-Up
Measurement Set-Up
Video: 10 steps grey scale
No audio
Video: 10 steps grey scale
No audio signal
RF_OUT Output Level
Measured picture carrier in dBµV with the HP8596E Spectrum Analyzer using a
75 to 50 Ω transformation, all cables losses and transformation pads having been
calibrated.
Measurement is used as a reference for other tests: RFout_Ref
Sound Subcarrier Harmonics
Measure in dBc second and third sound harmonics levels in reference to picture
carrier (RFout_Ref).
Picture carrier
Sound carrier
Sound
2nd harm
Sound
3rd harm
Fo +5.5 MHz +11 MHz +16.5 MHz
Second Harmonics of Chroma Subcarrier
No audio
Video: a 700 mV_(pp) 100 kHz sinusoidal
signal is inserted on the black level of active
video area.
Measure in dBc, in reference to picture carrier (RFout_Ref), second harmonic of
chroma at channel frequency plus 2 times chroma frequency, resulting in the
following spectrum.
Picture carrier
Frequency
Frequency
10¹0^00kk^HH^z z
700 mVpkpk
700mV pk-pk
Chroma
carrier
Sound
carrier
Chroma 2nd
Harmonic
Fo
+4.43 MHz +5.5 MHz
+8.86 MHz
MC44BC375U
8
Application Specific Products
Freescale Semiconductor