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TMS37157: Source for Hi Power readers?

Part Number: TMS37157
Other Parts Discussed in Thread: RI-STU-MRD2, MRD2EVM, TMS37126, TMS37F128, UCC27424

I am trying to develop a data logger application with the TMS37157 smart RFID chip. 

Can anyone help me find a HI POWER, LONG RANGE (1-2 meter) reader that will work with this chip?  I would prefer something that is in commercial production that we could buy off the shelf after arranging a demonstration with the manufacturer.

I would also enjoy chatting with anyone who has actually created a working application using this chip to share ideas and solutions.

Kelly Borsum, P.E., 1-619-794-7788 in southern California

  • Hello William,

    high power LF readers are no longer available from TI. We offer the RI-STU-MRD2 reader which can be used with the TMS37157.
    As long as I know there is a company that offers a combination of the MRD2 together with a power module.

    In any case to achieve a distance of 1m to 2m is a big goal. You will need large antennas on both sides. For the TMS37157 I would recommend a ferrite antenna.
    Read-Only transponders are working with power readers in this range. If this works also for the TMS37157 has to be evaluated because of its higher power consumption.

    Best Regards,
    Helfried
  • HI...Ive got one of the MRD2EVM readers, along with an ACC-ADR2-10 that was included in the original TMS37157 EVAL kit, and can talk to our TMS37157 boards successfully...the issue now is range. I've gotten several referrals to sources that have longer range readers, and will be following up on them immediately--including the one you sent.
    FYI, I was told that theTMS37157 EVM kit was discontinued due to problems getting antennas other than from Neosid (a totally useless supplier!). I found direct replacements from Coilcraft in their 4513TC series. They are not listed online, but we got 30 samples made to order in a couple of weeks, and they seem to work just fine.
    The antennas seem to be extremely directional. I've tried putting two of the ferrite antennas at 90 degrees, and adjusting the capacitor to give a resonance just below 134.2 KHZ. I seem to get a nice voltage generated on the tag board, but no communications. Any suggestions about this???
  • Hello William,

    you are talking about two ferrite antennas. Did you replace the reader side with a ferrite antenna?
    If this is the case then I assume the Q factor of the reader antenna is to high. The Q factor for the reader should be in the range of 10, otherwise the ASK modulated telegram from the reader is distorted and can not be detected by the tag.

    Best Regards,
    Helfried
  • Hi Helfried!

    First MANY thanks for the referral.

    Next, I used two ferrite antennas from Coilcraft that I've been using as direct replacements for the unavailable Neosids, and placed them on the TAG board with the TMS37157. I haven't modified either of the two readers I have.  I did the math and used a 2% cap that put the resonant frequency in the 130KHz range. The tag's voltage seemed to be reasonable in the 5-6V range, but there was no data coming back from the tag. I'll try it with a battery shortly and see what happens. Your friend indicated that two antennas at 90  degrees would give a 45 degree vector, and we really needed three separate antennas with their own drivers.

    One of the things that came out of the looong chat with the folks in Houston, there was and perhaps still is another chip that provided for 3-D antennas (3 separate circuits for three orthogonal antennas). He remembered it as having a part number something like TMS37126 and it was used as a smart tag in measuring displacement in bridge abuttments at about 20 feet deep. I did find a TMS37F128 3D keyfob, but we definitely need some way of transfering data from a uC at the TAG end. If you know of such a chip that existed at some time in the past, could you send me information on it?  I might be able to find some somewhere in the supply chain. If it is still in production, then you will probably hear the shouts of joy :-)

    The -128 3D tag included a design for driving three high power antennas separately using a UCC27424  (SCBA031). This might work for the reader, but we are thinking that the TAG also needs the 3D antenna system since there is know way we would know the orientation of the tag in the animal.

    Best regards for now.

    Kelly