TI E2E Community
Precision Amplifiers Forum
measuring Ro by both Load and Drive methods
Following Tim Green's article in Operational Amplifier Stability, part 3 of 15, I simulated an OPA364 on LTSPICE. The resulting Ro value is 152ohms vs. the 109 ohms that he gets in his article. Could the Tina spice model be different than the Pspice model? I noticed that the pspice model is dated 2004, while Tina's is 2009. Could this be the source of the difference?
I looked at the TINA model and although it was reloaded to the internet in 2009, it appears to be the same 2003 model used for the PSPICE version. I tested the model and here is the Zo curve that I received. I found a value of 107 Ohms which closely matches Tim's results of 109 Ohms.
There were some updates to Tim's testing methods for Zo that may not have been published. Backdriving the amplifier is the preferred choice to test Zo in SPICE.
Best Regards,Collin WellsPrecision Linear Applications
Regards,Collin WellsPrecision Linear Applications
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.