
No. 5693-3/6
LA7642N
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
Input a color bar signal (0 dB) to pin 14. In the
pin 6 (R-Y) output waveform measure the
amplitude of the blue green (+280 kHz) and
R-Y linearity
LINRY
red (–280 kHz) components (A) and measure
85
100
115
%
the amplitude of the blue (+45 kHz) and
yellow (–45 kHz) components (B). Calculate
the value of LINRY from the following formula.
LINRY = (A/B)
× (90/560) × 100 (%)
Measure the peak value of the pin 7 ALC
ALC pulse height
VALC
pulse signal.
180
200
220
mVp-p
Referenced to the blanking period DC level.
Blanking period B-Y DC voltage
VALC
The pin 7 blanking period DC level.
3.8
4.1
4.4
V
Blanking period R-Y DC voltage
VRYBLK
The pin 6 blanking period DC level.
3.8
4.1
4.4
V
The pin 7 output impedance. For reference
only.
Input a color bar signal (0 dB) to pin 14 and
measure the pin 7 B-Y amplitude Vb (V p-p).
SECAM output impedance: B-Y
ZBYS
Next, connect a 2-k
resistor between pin 7
150
and ground and measure the pin 7 B-Y
amplitude Vwrb (V p-p). Derive ZBYS from
the following formula.
ZBYS = (Vb – Vwrb)/Vwrb
× 2k ().
The pin 6 output impedance. For reference
only.
Input a color bar signal (0 dB) to pin 14 and
measure the pin 6 R-Y amplitude Vr (V p-p).
SECAM output impedance: R-Y
ZRYS
Next, connect a 2-k
resistor between pin 6
150
and ground and measure the pin 6 R-Y
amplitude Vwrr (V p-p). Derive ZRYS from
the following formula.
ZRYS = (Vr – Vwrr)/Vwrr
× 2k ().
The pin 7 output impedance. For reference
Output impedance
only.
Non-SECAM: B-Y
ZBY
Apply a 4-V signal to pin 7 (B-Y), measure
10
M
the influx current Ib, and derive ZBY from the
following formula. ZBY = 4/Ib (M
)
The pin 6 output impedance. For reference
Output impedance
only.
Non-SECAM: R-Y
ZRY
Apply a 4-V signal to pin 6 (R-Y), measure
10
M
the influx current Ir, and derive ZRY from the
following formula. ZRY = 4/Ir (M
)
The DC difference between the pin 7 no
signal period DC level and the signal period
Black level error B-Y
BBBY
DC level for a black-and-white signal.
–5
0
+5
kHz
Measure DBY (V) and calculate BBBY from
the following formula.
BBBY = DBY
× 460/VBY kHz
The DC difference between the pin 6 no
signal period DC level and the signal period
Black level error R-Y
BBRY
DC level for a black-and-white signal.
–5
0
+5
kHz
Measure DRY (V) and calculate BBRY from
the following formula.
BBRY = DRY
× 460/VRY kHz
[De-Emphasis Characteristics]
Input a signal to which a 63-kHz modulation
has been applied to pin 14 and measure the
pin 7 B-Y amplitude Vbon (V p-p) when
De-emphasis 63k B-Y
DE63B
preemphasis is on. Next, turn off pre-
–1.0
–2.6
–4.0
dB
emphasis, measure the pin 7 B-Y amplitude
Vboff (V p-p), and calculate DE63B from the
following formula.
DE63B = 20
× log (Vboff/Vbon) (dB)
Continued from preceding page.
Continued on next page.