AD7150 Internal Memory

Hi

we are considering the AD7150 for re-designing our sensors.

We have bought the evealuation board accordingly.

Now the problem is the following:

We need fixed threshold and the sensitivity needs to be tuned piece by piece once we ill be in commercial production.

We have set th AD7150 internal registers via evaluation board and relevant SW application.

The problem is that once the part it's turned off the settings are cleared from the internal memory.

Is there a way to use this sensor maintaining the internal storage settings after the device it's turned off?

  • 0
    •  Analog Employees 
    on Mar 11, 2013 6:41 PM

    Hello EuAle,

    Are you asking to change the default settings for all the parts, or do you mean that every part will get it's own individual settings?

    Regards,

    Sean

  • Hi Sean,

    thank you for your answer. I will explain better the above issue.

    We need to work with fixed treshold setting for several reasons to long to describe here (may be by phone).

    We tried your sensor and in our application we measured a baseline of 35.200 counts (decimal) and a detection

    value of 39.500 counts so settings the treshold in the middle we should be on safe, zone (at least theoretically) correct?

    With our current sensor, we are swapping out, we tune piece by piece. May be with yours would not be necessary

    (this depends on the variations we will experience on the PCB productions, components tolerance etc) so we could try to set by factory the relevant settings. (treshold-37.000, chip sensitivity-1 pF).

    This is the issue. We could be required to set piece by piece or if we are lucky we could set for all the parts.


    Can you please help?

    EuAle

  • 0
    •  Analog Employees 
    on Mar 12, 2013 4:06 PM

    Hello EuAle,

    Does the system not use a microcontroller?

    Our sensor and your sensor may have different baselines and these baselines will change depending on environment. This is the purpose of the Adaptive Threshold engine.

    Have you tested your sensors under all conditions?

    Regards,

    Sean

  • Hello Sean,

    we would avoid an MC due to complications in parts configuration during tuning process.

    In our application the sensor it's used as proximity switch measuirng the level of powerds into a metal tank.

    So the environment changes as low impact on that application.

    Conversely once the level of powerds approached the sensors edge starts a very slow variation of measured capaictance by the sensor as the powerds level varies very slowly then causing a missing detection with adaptive threshold.

    We have tested your sensor and it works with fixed threshold setting.

    Unfortunately the stored data settings are cleared at power off.

    Do you have available code download for MC (i.e. cypress, microchip, etc) to be used for your AD715x line?


    BRe

    uale

  • 0
    •  Analog Employees 
    on Mar 13, 2013 3:51 PM

    Hello EuAle,

    The AD715x devices have default settings for use without a MC and cannot be changed by software. Once the part has been powered up, the settings can then be changed, but any reset or power down will lose the changed settings and revert to the default settings.

    If you require different default settings, please contact your appropriate sales channel.

    There is no specific code download for use with the AD715x parts. They use a common I2C interface.

    Further information on the evaluation boards can be found at this question:

    http://ez.analog.com/thread/17701

    These use the same USB connection.

    Regards,

    Sean