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TMUX6221: Would this part work for 13.56MHz RFID (ISO15693, ISO 14443, etc.)?

Part Number: TMUX6221
Other Parts Discussed in Thread: TMUX7221, TMUX4827

Hello,

   I have an application where we have one RFID Transceiver (STMicro ST25R3916B) which outputs a differential antenna signal that then goes through an antenna mux to select one of 16 different PCB trace antennas. Antennas are small, about 1" in diameter and read distance is very close, maybe 0.5". Currently the antenna mux is just 16 different DPDT relays controlled by an MSP430. But we'd like to replace the relays with a silicon based solution for noise and cost. Would the TMUX6221 work? The antenna signal is bi-directional, about +-6V; see attached. I figure that we would need to power the chip with +/- 15V so there's plenty of headroom. The Ron of 2 ohms isn't a problem since I'm already attenuating both signals by a few ohms. According to the datasheet the -3dB bandwidth is 45MHz so it should be sufficient. If it matters, duty cycle is low, <1%. Finally, control logic voltage is 3.3V nominal but I can adjust that to whatever is needed.

I see also that there's the TMUX7221; is that just the same thing but can handle higher voltages? Any benefit?

There's also the TMUX4827 but that's in a tight 0.4mm pitch BGA which would require a higher spec board. It has a bandwidth of 72MHz but then Figure 6-22 in the datasheet says that above 50kHz the voltage swing is limited to +/-2V so that part is kinda sus.

Finally, how can I get samples of this or a development board to test? This would be a change to a product on the market already and volumes are decent.

Thanks,

Derek

 

  • Hello Derek,

    After looking into this  TMUX6221 or TMUX7221  are great options for this relay replacement application. The TMUX62221 bandwidth of 45MHZ means that there will be no significant attenuation of your systems signals when the signal is slower than that frequency which yours is. The duty cycle doesn't matter in this situation.  Check out this app note that talks more about replacing relays with multiplexers.

    In addition to order samples visit TI.com, type in the name of the product your are looking for  and click request sample.

    Please let me know if you require any further assistance 

    Regards,

    Kameron

  • Hello, when will the TMUX6221 or the TMUX7221 be available for purchase? Either TI e-store or through a franchised distributor.

    BTW, getting samples is not working right now; it re-directs me back to the customer support center home page.

  • Hello Derek,

    I think I understand what's going on. You might need to login to ti.com to buy the parts, get samples and see the inventory like I can.

     

    Please let me know if you need any other assistance.

    More than happy to help!

    Regards,

    Kameron

  • Hello, I was able to place a sample order for the TMUX6221 but then my sample order was cancelled. No indication about why. I'm trying again but are you actively sampling this part?

    When will the TMUX6221 / TMUX7221 be available in distribution?

  • Hello Derek,

    I am working on getting this issue fixed for you and am talking to another internal team to see what is the problem for this device on Ti.com

    I will update you on the status of this issue getting fixed Asap and should have some information before the end of this week if not sooner

    Regards,

    Kameron

  • Argh - I've put in two sample requests now: one for the TMUX6221 and one for the TMUX7221 but they've both been cancelled. How can I get these parts to test?

    Thanks,

    Derek

  • Hello Derek,

    Sorry for the issues with ordering these devices. I did contact our ti.com samples team and waiting for their response at this time.

    I will update you on the status of this issue getting fixed Asap and should have some information before the end of this week if not sooner

    Regards,

    Kameron

  • Hello Derek,

    Just as a quick update the TI.com samples team  has escalated this issue in priority and in the process of determine why your sample orders are getting canceled and when this issue can be resolved so you can get samples of these devices. You could try in the meantime and see if you could sample another mux device just to see if the sample request works for a different device.

    In the mean time here is a filter down list of devices that can support your +-15v supply. Some of the devices on this list are 1:1 2channel devices and some are 1:1 4channels devices. If you decide to sample with the 1:1 4channel device you could leave the  unused pins floating in this application.

    I will update you as soon as I have more information from the sample team. I will also update you with any new information later next week

    Regards,

    Kameron

  • Hello, could you please PM me with the sales contact for Southern California? This project is be a decent amount of TI silicon (each board is qty. 20 of TMUX6221s plus MSP430, power, etc.) so we'd like to speak to someone inside TI directly. Thanks

  • Hello Derek,

    Sorry for the late response. I am working on getting an update form TI.com samples team and see if I can get you in contact with a TI sales team member.

    Please allow our internal teams to find out some more information and I will update this thread as soon as I have more information

    Rgards,

    kameron

  • Hello Derek,

    After talking to the Internal TI sample team, it looks like now you should be able to order the samples from ti.com now.

    Please let me know if there is any other problems.

    Regards,

    kameron