AC Electical Characteristics (Continued)
T
A = 25C; VCC1 =VCC2 = 8V. Manually adjust Video Output pins 13, 15, and 18 to 4V DC for the AC test unless otherwise
stated. (Note 15)
Symbol
Parameter
Conditions
Typical
(Note 5)
Limit
(Note 6)
Units
V
sep 10 MHz
Video Amplifier 10 MHz Isolation
V
10 = 4V (Notes 11, 13)
50
dB
V
OL(OSD)
OSD Black Level, Difference from
Video Black Level
V
OSD in = 0.8V, OSD Mode
0.4
0.7
V (max)
V
OH(OSD)
OSD Output High Voltage (above
measured video black level)
V
OSD in = 2.5V, OSD Mode
2.1
2.4
V (max)
t
r(OSD)
Going into OSD Mode
OSD Mode (
Figure 2)
5.0
ns
t
f(OSD)
Going out of OSD Mode
OSD Mode (
Figure 2)
10.0
ns
t
r-prop(OSD)
Starting OSD Propagation Delay
Switching to OSD Mode (
Figure 3)
13.0
ns
t
f-prop(OSD)
Ending OSD Propagation Delay
Switching to Vid. Mode (
Figure 3)
14.0
ns
T
pw(Clamp)
Input Clamp Pulse Width
(Note 14)
200
ns (min)
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 de-
grade when the device is not operated under the listed test conditions.
Note 3: VCC supply pins 2 and 16 must be externally wired together to prevent internal damage during VCC power on/off cycles.
Note 4: Human body model, 100 pF discharged through a 1.5 k
resistor.
Note 5: Typical specifications are specified at +25C and represent the most likely parametric norm.
Note 6: Tested limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 7: The supply current specified is the current for VCC1 and VCC2 minus the current through RL (Isupply =ICC1 +ICC2 IL). The supply current for VCC2 (pin 16)
does depend on the output load. With video output at 1V DC, the additional current through VCC2 is 7.7 mA with RL = 390.
Note 8: Output voltage is dependent on load resistor. Test circuit uses RL = 390.
Note 9: Measure gain difference between any two amplifiers. VIN = 635 mVPP.
Note 10:
AV 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 (V10) at either 4V or 2V measured relative to an AV max condition, V10 = 4V. For example, at AV
max the three amplifiers’ 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 V10 = 2V. This yields the mea-
sured typical ± 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 socked is recom-
mended. 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 (AV max reference level) to the 3 dB corner frequency (f3 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 fIN = 10 MHz for Vsep 10 MHz.
Note 14: A minimum pulse width of 200 ns is guaranteed for a horizontal line of 15 kHz. This limit is guaranteed by design. If a lower line rate is used then a longer
clamp pulse may be required.
Note 15: During the AC test the 4V DC level is the center voltage of the AC output signal. For example, if the output is 4 VPP the signal will swing between 2V DC
and 6V DC.
Note 16: Machine Model ESD test is covered by specification EIAJ IC-121-1981. A 200 pF cap is charged to the specified voltage, then discharged directly into the
IC with no external series resistor (resistance of discharge path must be under 50
).
LM1279A
www.national.com
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