LMV225SDEVAL: LMV225SD/NOPB and LMV225SDX/NOPB are with different status
Part Number: LMV225SDEVAL
I'm testing the LMV225SDEVAL output voltage vs Input power at 868MHz. A repetitive DC offset is measured that causes a wrong output measurement.
Did you have any explanation
What are the output voltages you are seeing for the range of input power you are putting in?
What voltages are you applying to VDD and ENABLE?
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 David Chaparro:
The output voltage fits the datasheet curve with a offset voltage between 100mV and 175mV vs (Pin=-30dBm to -1dBm).
The Vdd and Enable voltage is 3V.
Thanks for supporting us.
In reply to houdali nabil:
For the offset voltage, are you seeing the 100mV above or below what the datasheet curve shows? If it is below, then there may be some loss in power somewhere in the setup.
The offset is above what the datasheet curve shows.
How are you producing the 868MHz signal? Are you connecting the signal directly to the evaluation board or is there something between them like an amplifier?
This is a pure 868MHz tone (no modulated signal). Yes, I connect the signal directly to the eval board.
Were any additional components installed on the evaluation board?
Are you able to verify the exact power level of the signal you are sending? Would it be possible for you to try with a higher frequency input and verify that you are seeing the same offset?
Yes, I'm able to ckeck the signal level at RFIN with a spectrum analyzer and it's done. I already tried with a higher frequency of 2GHz gave that gave me the same DC voltage.
What voltage do you read when there is no RF input?
Can you make sure that the 100pF coupling capacitor is installed on the EVM.
Yes there is a coupling capacitor but I can't know the value.
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.