
TA8701AN
2001-05-10
11
Note 11: Intermodulation
PIF input (Pin 4) : Input the following composite signals to the PIF input.
(1) SG1 : 58.75MHz (P) 84dBV
(2) SG2 : 54.25MHz (S) 74dBV
(3) SG3 : 55.17MHz (C) 74dBV
Monitor the video output (Pin 19-b) detection output waveform. Apply external voltage to the 2nd AGC
terminal (Pin 1) so that the waveform’s lowest level matches the sync. Tip level.
Using a spectrum analyzer, measure the difference between the level of the chroma signal component and
920kHz signal component.
Note 12: FM detection output
SIF input (Pin 16) : fo = 4.5MHz, fm = 400Hz, 25kHz / devi, 100dBV.
Measure the sound detection output of the sound output terminal (Pin 8).
Note 13: Limiting sensitivity
SIF input (Pin 16) : Input same as Note 12. Gradually reduce the input signal. Measure the input level when
the sound detection output of the sound output terminal (Pin 8) will be 3dB.
Note 14: AM Suppression ratio
SIF input (Pin 16) : fo = 4.5MHz, 84dBV.
Measure the sound detection output level of the sound output terminal (Pin 8) when the above signals are
modulated as follows. Calculate the ratio.
(1) AM modulation : fm = 400Hz, 30%
(2) FM modulation : fm = 400Hz, 25kHz / devi
[dB]
)
(mV
modulation
AM
with
)
(mV
modulation
FM
with
og
20
AMR
rms
rms
=
l
Note 15: 3dB bandwidth
SIF input (Pin 16) : fo = 4.5MHz, fm = 400Hz, 7.5kHz / devi, 100dBV.
(1)
fAfh: Gradually raise the frequency. Measure the input frequency when the sound detection
output of the sound output terminal will be 3dB.
(2)
fAFI: Gradually lower the frequency. Measure the input frequency when the sound detection
output of the sound output terminal will be 3dB.
3dB bandwidth = (fAFhfAFl) [kHz]