Driving capacitive loads with high-performance amplifiers is not a problem as long as certain precautions are taken. The THS413x have been internally compensated to maximize bandwidth and slew rate performance. When the amplifier is compensated in this manner, capacitive loading directly on the output decreases the device phase margin leading to high-frequency ringing or oscillations. Therefore, for capacitive loads of greater than 10 pF, place a resistor in series with the output of the amplifier, as shown in Figure 9-1. A minimum value of 20 Ω works well for most applications. For example, in 50-Ω transmission systems, setting the series resistor value to 50 Ω both isolates any capacitance loading and provides the proper line impedance matching at the source end.

Figure 9-1 Driving a Capacitive Load