AC Electrical Characteristics
See AC Test Circuit
(Figure 3)
T
A
e
25 C V
CC1
e
V
CC2
e
12V Manually
adjust Video Output pins 17 20 and 26 to 4V DC for the AC test unless otherwise stated (Note 14)
Symbol
A
V max
Parameter
Video Amplifier Gain
Conditions
V12
e
4V V
IN
e
635 mV
PP
V
drive
e
4V
2V
0 25V
Ref A
V
max V12
e
2V
Ref A
V
max V12
e
0 25V
Ref A
V
max V
drive
e
2V
Ref A
V
max V
drive
e
0 25V
V12
e
4V V
drive
e
4V (Note 9)
V12
e
4V to 2V (Notes 9 10)
V
O
e
1 V
PP
f
e
10 kHz
V12
e
4V V
drive
e
4V
V
O
e
4 V
PP
V
O
e
4 V
PP
LM1208
LM1209
LM1208
LM1209
t
f
(Video)
Video Output Fall Time (Note 11)
V
O
e
4 V
PP
LM1208
LM1209
V
sep
10 kHz
V
sep
10 MHz
t
r
(Blank)
t
f
(Blank)
t
pw
(Clamp)
Video Amplifier 10 kHz Isolation
Video Amplifier 10 MHz Isolation
Blank Output Rise Time (Note 11)
Blank Output Fall Time (Note 11)
Min Back Porch Clamp Pulse Width
V12
e
4V (Note 13)
V12
e
4V (Notes 11 13)
Blank Output
e
1 V
PP
Blank Output
e
1 V
PP
Typical
(Note 5)
70
16 9
b
6
b
40
b
6
b
40
g
0 3
g
0 1
Limit
(Note 6)
60
15 6
Units
V V (min)
dB (min)
dB
dB
dB
dB
dB
dB
%
MHz
DA
V 2V
DA
V 0 25V
DDrive
2V
DDrive
0 25V
A
V match
A
V track1
THD
f (
b
3 dB)
Contrast Attenuation
Contrast Attenuation
Drive Attenuation
Drive Attenuation
2V
0 25V
A
V
max
Absolute Gain Match
Gain Change Between Amplifiers
Video Amplifier Distortion
Video Amplifier Bandwidth
(Notes 11 12)
Video Output Rise Time (Note 11)
1
130
100
28
32
34
36
b
70
b
50
t
r
(Video)
ns
ns
dB
dB
ns
ns
ns
7
7
200
Note 1
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur
Note 2
Operating Ratings indicate conditions for which the device is functional but do not guarantee specific performance limits For guaranteed specifications
and test conditions see the Electrical Characteristics The guaranteed specifications apply only for the test conditions listed Some performance characteristics
may degrade when the device is not operated under the listed test conditions
Note 3
V
CC
supply pins 3 11 22 23 25 must be externally wired together to prevent internal damage during V
CC
power on off cycles
Note 4
Human body model 100 pF discharged through a 1 5 kX resistor
Note 5
Typical specifications are specified at
a
25 C and represent the most likely parametric norm
Note 6
Tested limits are guaranteed to National鈥檚 AOQL (Average Outgoing Quality Level)
Note 7
The supply current specified is the quiescent current for V
CC1
and V
CC2
with R
L
e
%
see
Figure 2鈥檚
test circuit The supply current for V
CC2
(pin 23) also
depends on the output load With video output at 1V DC the additional current through V
CC2
is 8 mA for
Figure 2鈥檚
test circuit
Note 8
Output voltage is dependent on load resistor Test circuit uses R
L
e
390X
Note 9
Measure gain difference between any two amplifiers V
IN
e
635 mV
PP
Note 10
DA
V
track is a measure of the ability of any two amplifiers to track each other and quantifies the matching of the three attenuators It is the difference in
gain change between any two amplifiers with the contrast voltage (V12) at either 4V or 2V measured relative to an A
V
max condition V12
e
4V For example at A
V
max the three amplifiers鈥?gains might be 17 1 dB 16 9 dB and 16 8 dB and change to 11 2 dB 10 9 dB and 10 7 dB respectively for V12
e
2V This yields the
measured typical
g
0 1 dB channel tracking
Note 11
When measuring video amplifier bandwidth or pulse rise and fall times a double sided full ground plane printed circuit board without socket is
recommended Video amplifier 10 MHz isolation test also requires this printed circuit board The reason for a double sided full ground plane PCB is that large
measurement variations occur in single sided PCBs
Note 12
Adjust input frequency from 10 MHz (A
V
max reference level) to the
b
3 dB corner frequency (f
b
3 dB
)
Note 13
Measure output levels of the other two undriven amplifiers relative to the driven amplifier to determine channel separation Terminate the undriven
amplifier inputs to simulate generator loading Repeat test at f
IN
e
10 MHz for V
sep 10 MHz
Note 14
During the AC tests the 4V DC level is the center voltage of the AC output signal For example if the output is 4 V
PP
the signal will swing between 2V DC
and 6V DC
3
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