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.

  • TI Thinks Resolved

ONET2804T: Application

Genius 11605 points

Replies: 5

Views: 366

Part Number: ONET2804T

My customer used our TI-TIA ONET2804T in their ROSA, when they test RSSI, they got split in different voltage input, please check the plot:

It was tested in Rrssi at 10kohm: (marked red in the second figure), his questions are:

1: why there are splits in the RSSI at different voltage

2. at what value we should set the Rrssi for the best performance, means close to ideal and no split.

Thanks.

  • Hello,

    Due to the holidays, we will have delayed responses. I will look into this issue and help resolve it or find an expert who can resolve this for you by the end of next week.

    Thanks!
    -Karan

  • In reply to Karan Kotadia:

    Hi Karan: Hope you had great holidays. Can you  please update on this open forum request. Customer is still waiting. Thanks

  • In reply to Naser S.:

    Hi Naser,

    Can you explain further what the customer means by different input voltages? Are they changing the power supply?

    The ONET2804T RSSI can have a gain variation as high as 8% from nominal with a 3.3V supply. The RSSI could change slightly with power supply due to the biasing of the circuitry changing slightly. However, I would expect that with the same supply and resistor value that they should be able to measure consistent values.

    Regards,

    Jacob Freet 
    High Speed Amplifiers

  • In reply to Jacob Freet:

    Hi Jacob:

    Yes the voltage change means the power supply change from 2.97V to 3.3V to 3.46V, if this will result 8% in gain difference, that explains the split.

    My questions is:

    Is there an optimal Rrssi set to make it works better?

  • Hi Naser,

    No the resistor value will just change the measured voltage relative to the resistor value. The RSSI signal is essentially a mirrored current so it is just multiplied by whatever resistor value you choose.

    Regards,

    Jacob Freet 
    High Speed Amplifiers

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.