Datasheet

+
_
THS306x
C
LOAD
Input
Output
R
g
10 Ω
R
f
V
I
V
O
C1
+
–
R
g
R
f
R1
f
–3dB
+
1
2pR1C1
V
O
V
I
+ ǒ1 )
R
f
R
g
Ǔ
ǒ
1
1 ) sR1C1
Ǔ
THS3061
THS3062
SLOS394B –JULY 2002–REVISED NOVEMBER 2009 www.ti.com
and should not be considered when using a
current-feedback amplifier. Because of this,
integrators and simple low-pass filters, which are
easily implemented on a VFB amplifier, must be
designed slightly differently. If filtering is required,
simply place an RC-filter at the noninverting terminal
of the operational-amplifier (see Figure 54).
Figure 53. Driving a Capacitive Load
General Configurations
A common error for the first-time CFB-amplifier user
Figure 54. Single-Pole Low-Pass Filter
is creating a unity gain buffer amplifier by shorting the
output directly to the inverting input. In this
configuration, a CFB amplifier oscillates, and is not
recommended. The THS306x, like all CFB amplifiers,
must have a feedback resistor for stable operation.
Additionally, placing capacitors directly from the
output to the inverting input is not recommended,
because at high frequencies, a capacitor has a very
low impedance. This results in an unstable amplifier
18 Submit Documentation Feedback Copyright © 2002–2009, Texas Instruments Incorporated
Product Folder Link(s): THS3061 THS3062