EL4089C

DC Restored Video Amplifier

Table of Charge Storage Capacitor vs Droop Charging Rates

Cap Value

Droop in 60 ms

Charge in 12 ms

Charge in 4 ms

nF

mV

mV

mV

10

6

36

120

33

18

11

36

100

06

36

12

Basic formulae are

Capacitor

Sample time

Capacitor

For best results the source impedance should be

kept low using a buffer for example

Because the SH 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

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