Datasheet

V
OCM
15V
V
S
R
S
R
G
R
F
R
F
+
R
T
+
R
G
C
G
0.1 mF
C
G
THS4500/2
V
DD
C
S
C
S
R
L
V
OD
=26V
PP
R
ISO
R
ISO
-
-
+
+
V
OCM
12-Bit/80MSPS
IN
IN
5 V
CM
5 V
5 V
V
S
10 mF 0.1 mF
10 mF 0.1 mF
THS4503
R
F
R
F
C
F
C
F
1 mF
R
G
R
G
0.1 mF
R
T
R
S
ADS5410
R
ISO
R
ISO
-
-
+
+
V
OCM
14-Bit/40MSPS
IN
IN
5 V
CM
5 V
V
S
10 mF 0.1 mF
THS4501
R
F
R
F
C
F
C
F
1 mF
R
G
R
G
R
T
R
S
ADS5421
0.1 mF
R
ISO
R
ISO
-
-
V
S
R
S
R
G1
R
F1
R
F2
+
R
T
+
V
O
R
ISO
C
C
F2
C
F1
R
G2
R
ISO
-
-
THS4500
THS4501
SLOS350F –APRIL 2002–REVISED OCTOBER 2011 www.ti.com
Figure 104. Fully Differential Line Driver With
High Output Swing
Figure 102. Using the THS4503 With the ADS5410
FILTERING WITH FULLY DIFFERENTIAL
AMPLIFIERS
Similar to single-ended counterparts, fully differential
amplifiers have the ability to couple filtering
functionality with voltage gain. Numerous filter
topologies can be based on fully differential
amplifiers. Several of these are outlined in the
application report A Differential Circuit Collection
(literature number SLOA064), referenced at the end
of this data sheet. The circuit below depicts a simple,
two-pole, low-pass filter applicable to many different
types of systems. The first pole is set by the resistors
and capacitors in the feedback paths, and the second
pole is set by the isolation resistors and the capacitor
across the outputs of the isolation resistors.
Figure 103. Using the THS4501 With the ADS5421
FULLY DIFFERENTIAL LINE DRIVERS
The THS4500 family of amplifiers can be used as
high-frequency, high-swing differential line drivers.
The high power-supply voltage rating (16.5 V
absolute maximum) allows operation on a single 12-V
or a single 15-V supply. The high supply voltage,
coupled with the ability to provide differential outputs,
enables the ability to drive 26 V
PP
into reasonably
heavy loads (250 Ω or greater). The circuit in
Figure 105. A Two-Pole, Low-Pass Filter Design
Figure 104 illustrates the THS4500 family of devices
Using a Fully Differential Amplifier With Poles
used as high-speed line drivers. For line driver
Located at: P1 = (2πR
F
C
F
)
–1
in Hz and
applications, close attention must be paid to thermal
P2 = (4πR
ISO
C)
–1
in Hz
design constraints because of the typically high level
of power dissipation.
Often, filters like these are used to eliminate
broadband noise and out-of-band distortion products
in signal acquisition systems. It should be noted that
the increased load placed on the output of the
amplifier by the second low-pass filter has a
26 Submit Documentation Feedback Copyright © 2002–2011, Texas Instruments Incorporated
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