Hello Chuchen,
We have several resources on this topic. The first is a TI Design (TIPD) that discusses the issue in depth. The second resource is a TI Precision Labs Op Amp Video/Slides set explaining the Riso method for maintaining stability with…
Other Parts Discussed in Thread: INA155 , TIPD128 Hello,
i have a problem with the INA155, I have the circuit posted in the schematic. In the bottom part there is the reference use to create the Vref (400mV) on GND1 and at the input pin of the opamp i have…
Check out the VCOM OUTPUT section of the datasheet regarding drive capabilities.
As previously mentioned, a buffer circuit that is not just a simple voltage follower may need to be employed if you are driving a large capacitance directly on the output…
Hi Fer Bar,
Try removing the capacitors at the output of the INA122. Capacitive loads can cause a circuit to become unstable. Please see this TI Design on driving capacitive loads http://www.ti.com/tool/TIPD128?keyMatch=tipd128&tisearch=Search-EN.…
Other Parts Discussed in Thread: INA121 , INA129 , TIPD128
Hi,
1. What will be the open loop output impedance of INA129 and INA121?
2. Is there a way to use the INA spice model and extract the model of 3 opamps inside these INAs seperately to check the…
Hello,
I believe you are refering to the paragraph on page 14 of the datasheet discussing CAPACITIVE LOAD AND STABILITY. The paragraph states that the OPA322 will remain stable in unity-gain with a pure capactive load of 1nF. Figure 33 shows a graph for…
Hello Anil,
Thanks for the new schematic and clarification. My only additional comment is that C105 is large and may cause stability issues for the OPA313. According to the OPA313 data sheet (Figure 21) you should reduce it to 50pF to maintain 45degrees…
Hello Ryuji,
I would expect some gain peaking with the circuit you have described. There are three causes to the gain peaking; a capacitive load of 100pF and 1000pF, large feedback resistor (100kohm), and a capacitor on the inverting input of the op amp…
