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.
Is there any problem with an inductive circuit (magnetic-field coil) on the input to the THS4524?
In the gain calculation, is the gain just Rf/Rg, where Rg is the magnitude of the impedance of the coil?
The Inductive circuit you mentioned in the EVM are actually transformers. On the input side of EVM, these transformers are not populated even if they are shown in the schematic. On the output side, these Transformers are used to convert the differential output of THS4524 to single ended outputs.
The gain is calculated from Rf/Rg where Rf is the feedback resistor and Rg is the gain set resister. There is no Impedance of the coil coming in the gain equation since the input side of EVM is not using a transformer. Please refere to Sec 9.2.3 and 9.2.4 of THS452x Datasheet for various configurations of using THS4524.
Thanks and regards,
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 Eldho George:
Since we are operating in the kHz range, we are not using any transformers on this board.
The input signal comes from a magnetic-field sensing coil, which has a substantial inductance.
I understand that in the gain equation, Rg includes all resistance in the input circuit, including in this case, the resistance of our magnetic-field sensing coil.
Should the inductive reactance of our input coil (2*pi*f*L) be included in a vector sum with the coil R in order to calculate the Rg that is used in the gain equation?
In reply to Ben Sternberg:
In reply to Samir Cherian:
Yes you would just use the vector sum. You can simulate this in TINA-TI a Spice tool. Its a lot easier. The link is below. You should have some resistance on that resistor pad to isolate the PCB and trace capacitance from the input of the amplifier.
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.