Application information

TSX920, TSX921, TSX922, TSX923

20/32

DocID024310 Rev 4

5.6

Capacitive load

Driving a large capacitive load can cause stability issues. Increasing the load capacitance

produces gain peaking in the frequency response, with overshooting and ringing in the step

response. It is usually considered that with a gain peaking higher than 2.3 dB the op-amp

might become unstable. Generally, the unity gain configuration is the worst configuration

for stability and the ability to drive large capacitive loads. Figure 39: "Stability criteria with a

serial resistor" shows the serial resistor (Riso) that must be added to the output, to make

the system stable.

Figure 39: Stability criteria with a serial resistor

Figure 40: Test configuration for Riso