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DRV411: Internal Circuit for driving hall sensor

ttd
Mastermind 7670 points
Part Number: DRV411
Other Parts Discussed in Thread: DRV421

Dear Technical Support Team,

About internal Circuit for driving hall sensor, is there output register inside of DRV411 on Hall1,2,3,4(from 17pin to 20pin)?

If there is output register, could you share the register value?

I have a plan to expand operation temperature on our environment and it seems to derate applied power of hall sensor.

 

Best Regards,

ttd

  • 0
    TI__Mastermind 26485 points

    Hello ttd,

    The hall sensor pins do two things they drive the current and measure the voltage and it is done on all pins.  There is no digital communication of I2C or SPI.  In the datasheet it explains the current spinning method which helps with some of the hall sensors drift and offset.  There is a condition you can place the DRV421 described in the datasheet that you can bypass this spinning current, but it still drives current and measures voltage.

    There is no digital communication so I do not understand what you are mentioning when you mention register value.

  • 0 in reply to Javier Contreras4
    Mastermind 7670 points

    Hi Javier Contreras,

    Thank you for your reply.

    I wrote typo on my post.  Correctly, internal resistance value (Not register value for digital interface).

    Does DRV411 be designed to limit with internal output resistance simply or not? 

    According to datasheet, control circuit is patented(0.95V max and 10mA max).

    So it is not simple structure. If you have any detail documentation of circuit, could you share it? 

     

    The DRV411 contains patented excitation and conditioning circuitry that significantly reduces offset and offset drift.

    The excitation circuit regulates the voltage across the hall element to a maximum voltage of 0.95 V.

    This voltage is very stable across the full temperature range. The excitation current varies with temperature

    in order to keep the hall sensitivity constant. A special current limiting circuit limits the current delivered to

    the hall element to a maximum current of 10 mA regardless of the temperature or the impedance of the hall element.

    Best Regards,

    ttd

  • 0 in reply to ttd
    TI__Mastermind 26485 points

    Hello  ttd,

    The part delivers a current that creates an excitation voltage between 0.6V and 0.95V.  The current is then limited to 10mA.  There is no internal resistance you can account for as it will not behave like one.  

    One way to think of it is that the hall excitation will drive the hall element to about 0.8V but it is limited to 10mA.

    We do not have more detailed documentation to share at the moment.  Can you share the hall element you are attempting to drive.  Is the resistance smaller than 0.95V/10mA=95Ω at the extreme temperatures?