The dynamic characteristics of the OPA1662 and OPA1664 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 (R_S equal to 50Ω, for example) in series with the output.

This small series resistor also prevents excess power dissipation if the output of the device becomes shorted. Figure 5-25 illustrates a graph of Small-Signal Overshoot vs Capacitive Load for several values of R_S. Also, refer to Applications Bulletin AB-028 (literature number SBOA015, available for download from the TI web site) for details of analysis techniques and application circuits.

(1) For measurement bandwidth, see Figure 5-7 through Figure 5-12.

Figure 6-5 Distortion Test Circuit