Datasheet

470 W 470 W
+15V
-15V
75 W
75 W
75 W
75 W
75 W
V
I
n lines
75- TransmissionLineW
V
O(n)
V
O(1)
THS3125
R
F
470 W
49.9 W
R
49.9 W
T
R
G
470 W
50- LoadW
50- SourceW
V
I
+V
S
+V
S
/2
+V
S
/2
THS3125
R
F
470 W
49.9 W
50- LoadW
+V
S
+V
S
/2
56.2
R
W
T
R
G
470 W
50- SourceW
V
I
+V
S
/2
60
50
40
30
20
10
0
RecommendedR Resistance( )W
ISO
10 100
C CapacitiveLoad(pF)-
L
THS3122
THS3125
SLOS382D –SEPTEMBER 2001–REVISED FEBRUARY 2011 www.ti.com
Single-Supply Operation
The THS3125 and THS3122 have the capability to
operate from a single supply voltage ranging from 10
V to 30 V. When operating from a single power
supply, biasing the input and output at mid-supply
allows for the maximum output voltage swing. The
circuits in Figure 39 show inverting and noninverting
amplifiers configured for single-supply operation.
Figure 40. Video Distribution Amplifier
Application
Driving Capacitive Loads
Applications such as FET drivers and line drivers can
be highly capacitive and cause stability problems for
high-speed amplifiers.
Figure 41 through Figure 47 show recommended
methods for driving capacitive loads. The basic idea
is to use a resistor or ferrite chip to isolate the phase
shift at high frequency caused by the capacitive load
from the amplifier feedback path. See Figure 41 for
recommended resistor values versus capacitive load.
Figure 39. DC-Coupled, Single-Supply Operation
Video Distribution
The wide bandwidth, high slew rate, and high output
drive current of the THS3125 and THS3122 match
the demands for video distribution to deliver video
signals down multiple cables. To ensure high signal
quality with minimal degradation of performance, a
0.1-dB gain flatness should be at least 7x the
passband frequency to minimize group delay
Figure 41. Recommended R
ISO
vs Capacitive
variations from the amplifier. A high slew rate
Load
minimizes distortion of the video signal, and supports
component video and RGB video signals that require
fast transition times and fast settling times for high
signal quality. Figure 40 illustrates a typical video
distribution amplifier application configuration.
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Product Folder Link(s): THS3122 THS3125