• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 3 answers
  • Subscribers 21 subscribers
  • Views 552 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

LMX2595EVM: LMX2595EVM

singam vamshi krishna
Intellectual 775 points
Part Number: LMX2595EVM
Other Parts Discussed in Thread: LMX2595, USB2ANY, PLLATINUMSIM-SW

Hello. As there is a 10 pin connector on the Reference pro Board side and at the serial interface of LMX2595EVM side. Now I would like, to realize this. So, I am planning to program controller and instead from the reference pro board I am planning to connect the pins from the programmed controller to the pins of serial interface of LMX2595EVM. Will that work, or else any further precautions to be taken.

Any Suggestions will be greatly appreciated.

Thanks in Advance.    

  • 0
    TI__Genius 11900 points

    Hello Singam,

    Yes, you should be able to put the USB2ANY/Reference Pro circuitry and LMX2595 on the same PCBand program the MSP430 to control the LMX2595. However for simplicity you may want to  tie some pins that are traditionally programmed through the Reference Pro directly to GND or VCC depending on your application and leave only the SPI interface through the MSP430. This is up to you.

    Thanks,

    Vibhu

  • 0 in reply to Vibhu Vanjari
    Intellectual 775 points

    Thanks for the response. I mean to say that specifically I am isolating the Reference Pro Board, Instead I am planning to make use of controller that supports SPI and from there I take female to female jumper and connect controller externally (Launch Pad Kit or Any other programming development Board) to LMX2595EVM in such a way that MISO to SDI, CLK to SCK, GND to GND and SS to CSB, leaving the remaining pins unconnected. Unconnected pins in the sense that Muxout, sync, RampCLK, SysRefReq,RampDIR leaving these pins unconnected. will this work, As I am transferring 24-bit data of about 79-registers and leaving the optional registers. 

    After performing this I connect the RFoutA to the Analyzer and I expect the desired frequency at the output.

    Is this enough or any further precautions to be taken. 

    Thanks in Advance.

  • 0 in reply to singam vamshi krishna
    TI__Genius 11900 points

    Hello Singam,

    Make sure it can be configured to meet the 6.6 Timing Requirements and DIGITAL INTERFACE voltage levels.

    RampDIR, RampCLK and SYNC can be left open or connected to GND.

    SYSREFREQ can be left open or connected to GND if unused.

    Muxout may be useful for debug, you can readback registers or use as lock detect.

    You can also use R58[15] = 1 (INPIN_IGNORE) to "Ignore SYNC and SysRefReq Pins"

    One correction, I believe you meant to say MOSI to SDI.

    Thanks,

    Vibhu

  • 0 in reply to Vibhu Vanjari
    Intellectual 775 points

    Yes its  MOSI to SDI. Regarding the voltage levels I am pretty sure that the Master Controller operates at 3.3V.

    1)Now in this case can I connect the Muxout pin to LED as indicator.

    2) What should be the delay after the transfer of one complete set of one 24-bit data. Is 100us okay or else 10ms ??

    3) I regret but I was not clear about the R58[15]=1. Do you mean to say that the 15th bit of R58 register is to be 1??

    4) What would be the switching time of the LMX2595 , I mean to say that to shift from one frequency to another frequency.  

    5) The Master Controller by default is set to 84MHz. Is that sufficient I mean I guess it should be divided to some integer value. what is the minimum clock frequency to match with the master speed?

    Thank you for your patience reply and further help will be appreciated. 

  • 0 in reply to singam vamshi krishna
    TI__Genius 11900 points

    Hello Singam,

    1. Yes you can connect Muxout pin to LED to indicate lock, you can alternatively use it for register readback. Please refer to EVM for example.
    2. The "Timing Requirements" section of the datasheet indicate this.
    3. If you do not plan to use SYNC and SysRefReq pins, then please set  the 15th bit of R58 register is to be 1.
    4. You can simulate the lock time, from one frequency to another, for a particular loop filter using PLLATINUMSIM-SW
    5. The SPI Write speed can be at most 75 MHz and readback at most 50 MHz. I assume this is what you mean by the master controller.

    Thanks,

    Vibhu