EL4089C
EL4089C
DC Restored Video Amplifier
Table of Charge Storage Capacitor vs Droop Charging Rates
Cap Value
nF
10
33
100
Droop in 60
ms
mV
6
18
06
Charge in 1 2
ms
mV
36
11
36
Charge in 4
ms
mV
120
36
12
Basic formulae are
V (droop)
e
Ib
a
(Line time
b
Sample time) Capacitor
and V (charge)
e
I
OUT
Sample time Capacitor
For best results the source impedance should be
kept low using a buffer for example
Because the S H effectively shorts the input sig-
nal during Sample the input should not be sam-
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
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
Life Support Policy
January 1996 Rev B
Elantec Inc
1996 Tarob Court
Milpitas CA 95035
Telephone (408) 945-1323
(800) 333-6314
Fax (408) 945-9305
European Office 44-71-482-4596
8
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
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
in Life Support Systems are requested to contact Elantec Inc
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-
sons or property or other consequential damages
Printed in U S A
ELANTEC [ ELANTEC SEMICONDUCTOR ]
