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TDC7200: TDC7200

Prodigy 80 points

Replies: 5

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Part Number: TDC7200

I take the TDC7200 and TDC1000  to drive the Ultrasound sensor , but there is a problem with the TDC7200.

TDC7200 works in the measurement MODE 2 for single stop ,  read the TIME2 register , it can be found that when the value of TIME2 decrease to about  200- ,the value will jump to 2000+,  refer to the FIG. as follows:

I  have tried to set the NUM_STOP for  more  the stops , and read the TIMEn  register value,

this jumping problem is turning cycle sitll when the TIMEn  register value hit the 200- and  2000+ (dec) ,  the curve as below:

I make sure that the  signal of  Ultrasound sensor  is linear  , there is no jumping !

I guess there are some thing wrong with the TDC7200 setting or TIMEn register .

Need  help ,  thank you!

  • Hello,

    Please provide me more info about your setup and the device register map to understand your problem better.

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to Bharat Aravamudhan:

    Hi,Bharat

    the setting of TDC7200 as bellow, FYI

    1. TDC7200 setup:

    TDC7200: in mode #2, one stop signal,

    calibration is always performed at the end,

    parity bit disabled,

    calibration2  by 20 periods of CLOCK,

    TRIGG START STOP is a rising edge signal,

    1 measurement cycle only,

    delayed by 3.0 sec relative to START pulses

    control parameter is – MEAS_COMPLETE_FLAG

    COARSE_CNTR_OVF_H/L=0XFFFF

    CLOCK_CNTR_OVF_H/L=0XFFFF

    CLOCK_CNTR_STOP_MASK_H/L=0X0000

  • In reply to user1075061:

    Hello,

    I am still working on your request and unable to replicate this issue, please give me a week's more time to find out this issue.

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to user1075061:

    Hello,

    Please let me know if you can provide me the delay between the STARt & STOP signal that you are trying to measure. Also you say "delayed by 3.0 sec relative to START" does that mean you do 1 measurement cycle every 3 sec ? or is the STOP delay from the START by 3s.

    Also as in Figure 18 in datasheet: TIME1 is occurrence of START edge to first clock edge. TIME2 is occurrence of STOP edge to next clock edge. So if your Time 1 alone is cyclic then ti could be due to the change in START happened closer to first clock edge. Note that the clock timing and your signal timing will be in sync always and that can create this changes.

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to Bharat Aravamudhan:

    Hi, Bharat

     I think the issue has been resolved as your remind. 

    Thank you!