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LMX25311570EVAL: EVM does not draw any current from power supply

Sam Huang32
Prodigy 210 points

Part Number: LMX25311570EVAL
Other Parts Discussed in Thread: USB2ANY, LMX2531, LMX2487E

I am having a problem when using this EVM. Since I don't have the USB2ANY interface to connect EVM to PC, I connected the 5V to CE and 3V to Vcc in order to let the EVM free run.

(Without connecting other pin like CLK, DATA, LE etc.)

However the EVM does not draw any current from my power supply. Did I miss anything?

  • 0
    TI__Expert 8865 points
    Hello Sam,
    Thanks for contacting us. Your question is assigned to an expert and he will get back to you as soon as possible.
    Best regards
    Puneet
  • 0
    TI__Mastermind 28031 points
    Sam,

    My suspicion is that the device may be powered down. The LMX2531 series devices has a chip enable pin, and if this is low, the device is powered down. Here's what I would check:

    1. Ensure you have a 10 MHz input reference hooked up.
    2. Ensure the CE pin on the programming GUI is checked and push Ctrl+L to load all registers. You should draw about 30 mA
    3. Ensure that the CE pin is high on the board. This is the intersection at resistors R8 and R9. If not already, remove R9 and place R8 and then it will always be pulled high.
    4. If using the TICSPro software, this requires a converter board. I see no mention of this in the instructions, but it should be. This converter board switches the signals around (CLK, Data, LE) so that it is compatible with USB2ANY. Check the back of these instructions for the LMX2487E and you will see a table for this with the proper jumper placement for the LMX2531. Link is here: www.ti.com/.../snau137a.pdf

    Regards,
    Dean
  • 0 in reply to Dean Banerjee
    Prodigy 210 points

    Hi Dean,

    Thanks for the reply!

    My EVM does not connect to PC. So I didn't use any kind of programming GUI, just tried to connect it to a power supply and let it free run.

    I do connect a 10MHz reference clock to OSCin, and 5V to CE pin (connect on MicroWire pin). I also measured the voltage on R8 whose voltage is over 2V so I think the CE pin is high.

    All the jumpers are placed correctly and voltage on C9, C12, C17, C18 are 3V.

    I have no clue about what's going on after checking all the parts/devices are connected properly.

    Sam

  • 0 in reply to Sam Huang32
    TI__Mastermind 28031 points
    Sam,

    The EVM must be programmed to get any meaningful output. This device has no power on reset; if you do not program it, then you have to assume the programming bits are random. As there are several software power down bits, it is very possible that one of them could be in the powerdown state if not programmed.

    For this board, we used to ship these with parallel port cables, but many computers do not have parallel ports. I thought we were shipping these with USB2ANY, which works with TICSPro and the USB port. The USB2ANY has a converter board that comes with it. Did you get a USB2ANY board?

    Dean
  • 0 in reply to Sam Huang32
    TI__Genius 9920 points

    Hi Sam,

    Please use GUI and cable to control the EVM as User Guide . Without register configuration, LMX2531 can't work in normal mode.

    In power down mode, 7uA is hard to be detected.

    If your PC has a parallel port, you could use the cable DB25-uWire (included in EVK), operate it as User Guide. The GUI is Codeloader. It is very easy. 

    If your PC does not have a parallel port but have a USB port, you need a USB2ANY box and a interface conversion board, operate them as above Dean's steps. The GUI is TICS Pro.

    Best Regards,

    Shawn

  • 0 in reply to Dean Banerjee
    Prodigy 210 points
    Dean,

    I just received the USB2ANY. However, I didn't find the converter board.
    I assume the converter board convert the pin definition of USB2ANY into the definition of EVM.
    So maybe I can pick up the DATA, CLK, LE, CE pins on the USB2ANY output and connect these to EVM?
    Can you tell me which pins should I choose on USB2ANY if possible?

    Thank you,
    Sam
  • 0 in reply to Sam Huang32
    TI__Guru** 120110 points
    Hi Sam,

    USB2ANY definition: LE (pin2), DATA(pin4), GND(pin6), CLK(pin8), CE(pin10).
    uWIRE definition: DATA(pin4), CLK(pin6), LE(pin8), CE(pin10), GND(pin9).