TSV91x, TSV91xA

Application information

DocID12584 Rev 10

15/27

5

Application information

5.1

Driving resistive and capacitive loads

These products are low-voltage, low-power operational amplifiers optimized to drive rather

large resistive loads above 2

kΩ.

In a follower configuration, these operational amplifiers can drive capacitive loads up to

100 pF with no oscillations. When driving larger capacitive loads, adding a small in-series

resistor at the output can improve the stability of the device (Figure 19 shows the

recommended in-series resistor values). Once the in-series resistor value has been

selected, the stability of the circuit should be tested on bench and simulated with the

simulation model.

Figure 19: In-series resistor vs. capacitive load

5.2

PCB layouts

For correct operation, it is advised to add 10 nF decoupling capacitors as close as possible

to the power supply pins.

5.3

Macromodel

An accurate macromodel of the TSV91x is available on STMicroelectronics’ web site at:

www.st.com. This model is a trade-off between accuracy and complexity (that is, time

simulation) of the TSV91x operational amplifiers. It emulates the nominal performances of

a typical device within the specified operating conditions mentioned in the datasheet. It

helps to validate a design approach and to select the right operational amplifier, but it does

not replace on-board measurements.