el8300 Intersil Corporation, el8300 Datasheet - Page 11

• Manufacturer Part Number: el8300
• Description: 200mhz Rail-to-rail Amplifier
• Manufacturer: Intersil Corporation

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 75Ω video load. A 2V
sine wave is applied to Amp A and a 1V
is applied to Amp B. Figure 31 shows the ENABLE signal
and the resulting output waveform at V
break-before-make operation of the multiplexing. Amp A is
on and V
ENABLE signal is low and turns off in about 25ns when the
ENABLE signal is high. About 200ns later, Amp B turns on
and V
make operation ensures that more than one amplifier isn’t
trying to drive the bus at the same time.
V
IN
IN2
75Ω
IN1
is passed through to the output. The break-before-
FIGURE 28. SYNC PULSE REMOVER
is passed through to the output when the
1K
FIGURE 29. VIDEO SIGNAL
V
OUT
V
+
-
1K
5V
IN
M = 10µs/DIV
V
V
S+
S-
11
75Ω
OUT
P-P
. Observe the
2MHz sine wave
P-P
75Ω
2MHz
1V
0.5V
0V
1V
0.5V
0V
V
OUT
EL8300
B
A
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
configuration. The signal is AC coupled by C
are used to level shift the input and output to provide the
largest output swing. R
the virtual ground potential. R
resistors for the line. C
to minimize the droop of the luminance signal.
1V
2V
2MHz
2MHz
P-P
P-P
ENABLE
75Ω
75Ω
FIGURE 30. TWO TO ONE MULTIPLEXER
1K
1K
FIGURE 31. ENABLE SIGNAL
A
ENABLE
+
-
+
-
1
F
, C
M = 50ns/DIV
and R
+2.5V
-2.5V
1K
+2.5V
-2.5V
1K
2
and C
T
G
and R
set the AC gain. C
3
are selected big enough
3
75Ω
are the termination
B
1
. R
0V
-0.5V
-1.5V
-2.5V
1V
0V
-1V
1
and R
2
isolates
V
2
75Ω
OUT