JAJSGT8F June 2010 – March 2023 OPA140 , OPA2140 , OPA4140
PRODUCTION DATA
The dynamic characteristics of the OPAx140 have been optimized for commonly encountered gains, loads, and operating conditions. The combination of low closed-loop gain and high capacitive loads decreases the phase margin of the amplifier and can lead to gain peaking or oscillations. As a result, heavier capacitive loads must be isolated from the output. The simplest way to achieve this isolation is to add a small resistor (ROUT equal to 50 Ω, for example) in series with the output.
Figure 6-19 and Figure 6-20 illustrate graphs of Small-Signal Overshoot vs Capacitive Load for several values of ROUT. Also, see the Feedback Plots Define Op Amp AC Performance Application Bulletin, available for download from www.ti.com, for details of analysis techniques and application circuits.