11

Typical Applications

VIDEO SYNC PULSE REMOVER

Many CMOS analog to digital converters have a parasitic

latch up problem when subjected to negative input voltage

levels. Since the sync tip contains no useful video

information and it is a negative going pulse, we can chop it

off. Figure 28 shows a gain of 2 connections for EL8300.

Figure 29 shows the complete input video signal applied at

the input, as well as the output signal with the negative going

sync pulse removed.

MULTIPLEXER

Besides the normal power down usage, the ENABLE pin of

the EL8300 can be used for multiplexing applications.

Figure 30 shows two channels with the outputs tied together,

driving a back terminated 75

is applied to Amp B. Figure 31 shows the ENABLE signal

break-before-make operation of the multiplexing. Amp A is

ENABLE signal is low and turns off in about 25ns when the

ENABLE signal is high. About 200ns later, Amp B turns on

make operation ensures that more than one amplifier isn’t

trying to drive the bus at the same time.

SINGLE SUPPLY VIDEO LINE DRIVER

The EL8300 is wideband rail-to-rail output op amplifiers with

large output current, excellent dG, dP, and low distortion that

allow them to drive video signals in low supply applications.

Figure 32 is the single supply non-inverting video line driver

configuration and Figure 33 is the inverting video ling driver

are used to level shift the input and output to provide the

to minimize the droop of the luminance signal.

FIGURE 28. SYNC PULSE REMOVER

5V

1K

75

Ω

+

-

75

Ω

1K

75

Ω

FIGURE 29. VIDEO SIGNAL

1V

0.5V

0V

1V

0.5V

0V

M = 10µs/DIV

FIGURE 30. TWO TO ONE MULTIPLEXER

+2.5V

1K

2MHz

75

Ω

+

-

1K

75

Ω

-2.5V

75

Ω

B

+2.5V

1K

2MHz

+

-

1K

75

Ω

-2.5V

A

ENABLE

FIGURE 31. ENABLE SIGNAL

0V

-0.5V

-1.5V

-2.5V

1V

0V

M = 50ns/DIV

A

ENABLE

B

-1V

EL8300