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RF430cl330h

Tom Jones78
Prodigy 40 points
Other Parts Discussed in Thread: RF430CL330H

Hi, i have some questions about that chip. Sorry if some of these questions are basics.

if i connect VCC to 3,3V my compiler(dspic33f) shows target removed. I cant run programm when i connect 3,3 V to VCC. So i first at all cant connect VCC with µC. If i run the programm, then it seems MOSI Pin is working, but my mobile cant detect a nfc tag, so i cant write data into my mobile. I configured the pic as mentioned in the example code. Maybe its not working, bcs of VCC?

When the into Pin is going to be interrupted? If a tag is received? Can the programm work without the Into pin?

An other Problem is, when i use CS-Pin. When i connect CS PIN to RF430 it seems the pin is permanent on low, even thought µC shows it is not. 

i just tried to send vie SPI one Character. Is it needed to have an extra capacitor CCORE between VCORE and Ground, or it is already implemented in the circuit board? What about VCC and VSS is there a need to build capacitors, or its already implemented? Same question about ant1 and ant2 is there a need to expand the circuit board?

  • 0
    TI__Mastermind 44795 points

    Hi Tom,

    Are you using a TI evaluation board or your own custom board? 

    See figure 3-4 in the datasheet, which shows the required capacitors.  C1=1uF, C2=0.1uF, Ccore=0.47uF.  Ctune will depend on the inductance of your antenna coil.  See the antenna design app note below for details.  If you do not have the bypass capacitors, the IC will not work as expected.

    http://www.ti.com/lit/pdf/sloa197

    The INTO pin can be set to fire based on different events.  This is set in the Interrupt enable register(0xFFFA).  See table 5-13 of the datasheet.  You do not have to use the INTO pin.  If you are not going to use the INTO pin, you can leave it floating and set the general control register to disable interrupts(bit 2). 

    If you are using SPI mode, the CS pin must be set high at power up.  If the pin is floating, there is an internal pull up on the RF430CL330H which will raise it high.  After power up when SPI has been selected, CS pin operates as the normal chip select for SPI.  Section 5.3 of the datasheet describes this.

     

  • 0 in reply to Eddie LaCost
    Prodigy 40 points
    i use the "analog system lab kit pro" from ti. So u say i need to build extra C1, C2, Ccore and Ctune. it is not implemented in the cicuit? What would be ur recommendations for Ctune and the inductance?
  • 0 in reply to Tom Jones78
    TI__Guru* 91206 points

    TomJones78 - 

    its not really clear here how you might be using the Analog System Lab kit pro with the RF430CL330H - all i can see on that potentially is you are using the breadboard (which looks to me to be for throughhole parts) with the IC (which is surface mount) - is that correct?

    we could recommend an RF430CL330H EVM if that would be easier for you to use, as that kit you have is for learning about basic analog - sort of a BE&E kit. 

    regardless - you have built something - so in your case i think step one is to construct and then measure the coil you intend to use with the RF430CL330H.

    as the input capacitor of the part (at the ANT pins) is typically around 35pF, so this means (for example) if you make the inductance of the coil in the range of 3.85uH (measured at 13.56MHz), then this would resonant with that internal cap around 13.7MHz (the sloa197 app note Eddie pointed you to has this outlined on starting on page 7 ==>

    ) this is just an example that was done for an eval board. usually we are recommending that you make the coil value a little lighter, which allows you to add capacitance in parallel and have some "room" to tune the system you are making. So then for the coil value you have - you would then need to (using the formula: fc = 1/2pi*sqrtLC) rearrange it so that you are getting a Ctotal value

    (this would end up being (1/fc*2pi*sqrtL)^2 = C, then you would subtract input C of the IC to get Ctune value needed. 

    hope that helps you out. 

  • 0 in reply to Josh Wyatt
    Prodigy 40 points
    i think you helped me. i am not sure. i need to try your advices