OPA191_017 Datasheet, PDF (26/51 Pages) Texas Instruments – 36-V, Low Power, Precision, CMOS, Rail-to-Rail Input/Output, Low Offset Voltage, Low Input Bias Current Op Amp

OPA191, OPA2191, OPA4191
SBOS701A – DECEMEBER 2015 – REVISED APRIL 2016
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8.3.5 Capacitive Load and Stability
The OPAx191 features a patented output stage capable of driving large capacitive loads, and in a unity-gain
configuration, directly drives up to 1 nF of pure capacitive load. Increasing the gain enhances the ability of the
amplifier to drive greater capacitive loads; see Figure 55. The particular op amp circuit configuration, layout, gain,
and output loading are some of the factors to consider when establishing whether an amplifier will be stable in
operation.
G = +1 V/V
Time (2 Ps/Div)
Figure 55. Transient Response with a Purely Capacitive Load of 1 nF
Like many low-power amplifiers, some ringing can occur even with capacitive loads less than 100 pF. In unity-
gain configurations with no or very light dc loads, place an RC snubber circuit at the OPAx191 output to reduce
any possibility of ringing in lightly-loaded applications. Figure 56 illustrates the recommended RC snubber circuit.
±
Input
+
Output
R 619
C 320 pF
Figure 56. RC Snubber Circuit for Lightly-Loaded Applications in Unity Gain
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