Datasheet

1/2
OPA2889
+5V
+V
S
DIS
V /2
S
698W
200W
V
O
V
D
V
I
698W
50W
R
G
750W
R
F
750W
0.1 Fm
0.1 Fm
59W
+
6.8 Fm0.1 Fm
R
G
R
F
1/2
OPA2889
R
G
R
F
1/2
OPA2889
V
IN
R
L
V
OUT
+5V
-5V
G =
D
R
F
R
G
DIFFERENTIAL OPERATION
R
F
1/2
OPA2889
R
F
1/2
OPA2889
V
IN
R
L
R
G
+5V
-5V
G =1+
D
2R
F
R
G
OPA2889
www.ti.com ....................................................................................................................................................... SBOS373B – JUNE 2007 – REVISED AUGUST 2008
The other possibility is using the OPA2889 in a
differential configuration as shown in Figure 53 . This
figure illustrates the differential noninverting input
configuration which has the advantage of showing a
high input impedance to any prior stage.
Figure 51. DC-Coupled, G = +2, Single-Supply,
Specification and Test Circuit
Figure 52. Differential Inverting Specification and
Again, an additional resistor (50 Ω in this case) is
Test Circuit
included directly in series with the noninverting input.
This minimum recommended value provides part of
the dc source resistance matching for the
noninverting input bias current. It is also used to form
a simple parasitic pole to roll off the frequency
response at very high frequencies ( > 500MHz) using
the input parasitic capacitance. The gain resistor (R
G
)
is ac-coupled, giving the circuit a dc gain of +1, which
puts the input dc bias voltage (2.5V) on the output as
well. The output voltage can swing to within 1V of
either supply pin while delivering > 40mA output
current.
Figure 52 shows the inverting input differential
configuration used as the basis for the ± 5V and +5V
Typical Characteristics. This circuit offers a
combination of excellent distortion with low quiescent
current.
Figure 53. Differential Noninverting Specification
and Test Circuit
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Product Folder Link(s): OPA2889