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.
Part Number: OPA4188
I want to sampling the BUS voltage, the total voltage is about 800V(DC). I have adjusted to about 50V through precision resistance voltage divider, and then, use the OPA4188 to realize it. The simple circuit as below, the BU+-BU- is arrived about 50V.
So I want to seek advice from you. Is this have problem like design? Thanks very much.
Please understand that most of our engineers are out for the holidays. It is most likely that we won't address your question until early January 2017.
Applications Manager, General Purpose Amplifiers
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 Pete%20Semig:
Could you kindly help me to answer the problem? Thanks very much!
For this kind of application, please consider using INA149 - it can handle the input common-mode voltages up to 550V.
If you wish to implement a difference amplifier, you must reference the output to an independent voltage source - it may NOT be connected to the output as shown on your circuit diagram. Also, since this kind of application requires large input resistors, you should not use chopper applifier like OPA4188 (due to commutation of IB current spikes) but instead use a precision linear op amp like OPA4191 or OPA4192 - see below. You do not specify the supply voltage or differential signal thus circuit below may have to be adjusted to make sure that the Vcm does NOT exceed the Vcc voltage.
I also attached below the TINA-TI circuit so you may use it for your simulations.
Jin Differential Amp.TSC
Marek Lis, MGTSSr Application EngineerPrecision Analog - TI Tucson
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.