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.

TMAG5170-Q1: Temperature Threshold

Part Number: TMAG5170-Q1

Just wanted to continue the question previously asked here:

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1113407/tmag5170-q1-temperature-threshold-setting-with-lsb-corrosponds-4-26-c

I tried to recalculate the digital code for the temperature threshold using the new formula: 

Digital Code = ((Threshold temp - 25 C) * 256/65 +1094)/16

but I am stuck with the lower threshold calculation.  I am unable to get 0x31 from -53C

Sorry if this is a dumb question, but I think I need a little push into the right direction.

If possible, a breakdown of how the equation came to be would be great. e.g. where does 4.267C come into play, where does 1094 come from, and etc.

Thanks,

Jeff

  • Jeff, 

    I apologize, I think I must have made an error attempting to transpose my equation in excel back into text.  

    This might be an clearer approach:

    TEMP_THX_FS = 275

    Threshold Temp = TEMP_THX_FS- (127-Threshold Code) * 4.2666

    Thanks,

    Scott

  • Hopefully I'm understanding this correctly, but it seems that if I calculate for the Threshold Code, it won't be in 2's complement anymore as stated in the datasheet. I think that was where my confusing was, I calculated the threshold code, then convert it to 2's complement to get a completely different code.

  • Based on the values in the datasheet, it would not be necessary for the MSB to ever be set to a 1, so it should make no difference within the functional range of the device whether it were 2s compliment or not.