Question
The data sheet shows the ADA4806 driving a 10µF capacitive load as an ADC reference buffer. Doesn’t this heavy capacitive load make the amplifierunstable?
Answer
No, the ADA4806 is quite stable in this configuration. A capacitive load adds an extra pole to the amplifier transfer function that can affectstability in many cases. A common method of maintaining stability in this situation is to add a series resistor between the amplifier output and thecapacitive load. For very large capacitances only a small resistor is needed. In this case the capacitance is so large (10µF) that the combined PCBtrace resistance and ESR of the capacitor provide enough series resistance to keep the amplifier stable.