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.
current and voltage sensor circuit
Sorry to bother you but I'm still confused .I need to measure between voltage supply and power amplifier ( voltage range from 5- 30 V ,the current range from 150-900 mA and the signals bandwidth are 4MHz , 10MHz).I will probe the output voltage form the sensor.I tried to simulate the circuit but the result is not good.
Could you share your schematic that you used for the circuit simulation? What problem are you having?
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 Micah B Brouwer:
In reply to sattam alshali:
i Micah again
Sorry to bother you.
I tried to simulate the THS4131 which has around 15MHz but the result is not good.Would you mind check my schematic.
Thanks for your help
THS4131 High Side Schematic.TSC
You're welcome, I am here to help. In the future, please be specific about what kind of issue you are having. Saying the result is "not good" is not very helpful. What is not good about the circuit? What were you expecting?
You should remove R25 in your schematic, and then you will see the output voltage (Vadc) according to what you would expect, given that there is a 50mV drop across the sense resistor and the first stage is in a gain of 2 and the second stage is in a gain of 5, so a gain of 10 in total and an output of 500mV. This is from the equation at the bottom. Currently in your schematic with R25, it is creating a voltage divider between R7, R8, and R25, and so the output is reduced (~330 mV).
Also, it maybe be helpful in the future to simulate the voltage drop across the shunt resistor with a voltage generator. The below snip from the original TIDA-00976 file shows the signal generator being converted from single-ended to differential with voltage controlled voltage sources. TINA prefers using one voltage source and converting from single to differential rather than two separate voltage sources. This way you can run a transient simulation and see the results from a sine or square wave input.
Thanks a lot Micah.
Is there any reason to use 1kOhm for R15 or can I increase it to 20kOhm
Wishing you the best
R15 is to simulate the load that the amplifier is driving. In this case, the amplifiers are designed as an input to an ADC. You could increase R15 to 20k. If you take a look at figure 27 in the THS4131 datasheet, you will see how the differential load resistance affects the output voltage of the amplifier. The amplifier might not be able to drive small loads (<1K) to the full voltage range because it will be limited by the maximum output current. Probably not a problem in your situation, but something to keep in mind.
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.