cxa1700aq Sony Electronics, cxa1700aq Datasheet - Page 27

• Manufacturer Part Number: cxa1700aq
• Description: Luminance And Color Signal Processing For 8mm Vcr
• Manufacturer: Sony Electronics

Detailed Explanation of Measurement Method
(1) DEMOD LPF frequency characteristics measurement
Using the CXA1207A as a modulator, the configuration for SG41 is shown below.
First, without inputting SG54, adjust V
CXA1207A is 5MHz. Use V
OUT (Pin 43) output frequency fo of the CXA1207A, and then calculate the MOD gain using the following
equation.
The compensation values are derived from GMOD and from GDEMOD1 and GDEMOD2 of measurement
Nos. 48 and 50.
Next, in order to set the SG41 carrier frequency, adjust V
CXA1207A in standard mode is 4.8MHz and in Hi-8 mode is 6.7MHz.
In the above state, measure the I/O gain for the SG54 (200mVp-p/300kHz) input and P7 (Pin 7 DEMOD
OUT), with the gain for standard mode being G
Using these measured values and compensation values, the low frequency gain for DEMOD LPF is
determined using the following equations:
SG54
4700
Standard mode compensation value : G
Hi-8 mode compensation value :
Standard mode :
Hi-8 mode :
4700
1µ
CAR
V
CAR
GMOD =
54
CXA1207A
REC MODE
FM
MOD
fo (MHz)–5 (MHz)
CARO
500 (mV)
(SG41)
for the V
43
YRFOUT
G
G
G
CAR
C1
C2
LPF11
LPF21
CAR
SW41
= 20log [G
= 20log [G
so that the Y RF OUT (Pin 43) output frequency of the
LPF10
—27—
voltage. Next, apply V
= G
= G
41
LPF10
LPF20
YRFIN
and for Hi-8 mode G
MOD
MOD
CAR
- G
- G
LIM
(MHz/mV) x G
(MHz/mV) x G
C1
C2
CXA1700A to be measured
so that the Y RF OUT (Pin 43) output of the
(dB)
(dB)
DEMOD
CARO
LPF20
DEMOD1
DEMOD2
+ 500mV, measure the Y RF
.
LPF
(mV/MHz)]
(mV/MHz)]
7
CXA1700AQ/AR
DEMOD
OUT
P7