This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
I have some questions aboout opa2211A.Our customer use OPA2211AIDDA.
(1)thermal performancePlease let me know calculation of Tj.I understood that Tj=Ta+(Pd*θja).But this device has θjp.Please let me know calculation of TJ by θjp.
And should we use which thermal resistance value ?θJa or θJp?
(2)Output Short-Circuit of ABSOLUTE MAXIMUM RATINGS I can see the Output Shout-Circuit rating as "Continuous" in the datasheet.I think that we can connect OUTpin to V-pin directly, we can connect OUTpin to V+pin directly.But it is an opamp only in the dual package.
Is my understanding correct?
Best Regards,Ryuji Asaka
OPA2211AIDDA has power pad for better power dissipation, thus the thermal resistance,θjp, is given between the junction and power pad instead of junction to ambient, θja. Assuming that you will solder the power pad to PCB (minimizing θpb), in order to calculate a junction temperature,Tj, you also need to know the thermal resistance between your PCB (heat sink) and ambient, θba. Therefore, the full Tj equation is as follow:
Ta - ambient temperature Pd - power dissipation in the package
θjp - junction to pad thermal resistance θpb - pad to board thermal resistance (minimized by soldering thermal pad to PCB, (θpb=~0) θba - board to ambient thermal resistance
If you do not solder the thermal pad to the PCB, use θja for your worst case calculation (based on high-k board).
OPA2211 short-circuit function is only for protection of the IC from damage in case of accidental shorting of the output and thus shoud never be used intentionally - prolong exposure of IC to short-circuit condition will lead to degradation of IC performance and shortening life of the product.
OPA211 (single) may be left in short-circuit condition for prolong time without damaging the part BUT in case of the dual version ONLY one channel (at any given time) is allowed in short-circuit condition - see note(2) above - placing both channels of the dual package in short-circuit condition would result in doubling power dissipation in the package, which may lead to the violation of the absolute maximum junction temperature, Tj_max=200C (see table above).
Marek Lis, MGTSSr Application EngineerPrecision Analog - TI Tucson
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Marek Lis:
In reply to Ryuji:
The board to ambient thermal resistance, θba, depends on the physical PCB board layout of the (V-) plane connected to the thermal pad of OPA2211 package; for that reason, you should ask the board manufacturer to help you to calculate its value based on the actual size and shape of the (V-) metal layer. In case you cannot obtain θba, a prudent (conservative) approach would be, in fact, to use θja number for your worst case thermal analysis.
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. 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.