EL4089C
DC Restored Video Amplifier
Table of Charge Storage Capacitor vs Droop Charging Rates
Cap Value
nF
Droop in 60 ms
Charge in 1.2 ms
Charge in 4 ms
mV
mV
mV
10
33
6
1.8
0.6
36
11
120
36
100
3.6
12
Basic formulae are:
a
e
b
V (droop)
and V (charge)
Ib * (Line time
Sample time) / Capacitor
* Sample time / Capacitor
e
I
OUT
For best results the source impedance should be
kept low, using a buffer for example.
pled during active video. Typically the sample is
made during the back porch period of horizontal
blanking. For this reason color composite signals,
which have color burst on the back porch, can
not be passed. See EL2090 or EL4093 for this ap-
plication.
Because the S/H effectively shorts the input sig-
nal during Sample, the input should not be sam-
General Disclaimer
Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes
in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any
circuits described herein and makes no representations that they are free from patent infringement.
WARNING Ð Life Support Policy
Elantec, Inc. products are not authorized for and should not be
used within Life Support Systems without the specific written
consent of Elantec, Inc. Life Support systems are equipment in-
tended to support or sustain life and whose failure to perform
Elantec, Inc.
1996 Tarob Court
when properly used in accordance with instructions provided can
be reasonably expected to result in significant personal injury or
death. Users contemplating application of Elantec, Inc. products
Milpitas, CA 95035
in Life Support Systems are requested to contact Elantec, Inc.
Telephone: (408) 945-1323
(800) 333-6314
factory headquarters to establish suitable terms & conditions for
these applications. Elantec, Inc.’s warranty is limited to replace-
ment of defective components and does not cover injury to per-
Fax: (408) 945-9305
European Office: 44-71-482-4596
sons or property or other consequential damages.
8
Printed in U.S.A.
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