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TMP431: ALERT / THERM2 assert timing

Part Number: TMP431

Hi All,

I have a question about ALERT / THERM2 for TMP431.

Please tell me when the following register settings are asserted.
【Configuration register1 MASK(7)=0  AL/TH(5)=1】

In my opinion, when using the ALERT / THERM2 terminal as THERM,
I think that it will be asserted at the temperature limit value immediately regardless of the register setting of the Consecutive aler. Is this correct?

Also, I think that the differences between ALERT and THERM are as follows, but is this correct?
ALERT asserts Low on the violating number of consecutive times , and THERM asserts Low as soon as it violates.

Best Regards,
Ishiwata

  • Hi Ishiwata-San,

    Thank you for your question.

    In my opinion, when using the ALERT / THERM2 terminal as THERM,
    I think that it will be asserted at the temperature limit value immediately regardless of the register setting of the Consecutive aler. Is this correct?

    Per section 8.6.11 of the datasheet, the consecutive Alert Register will be used to determine when both the ALERT and THERM functions are activated. In other words, if you had [CALT2:CALT0] = b111, then it will take 4 out of limit measurements to trigger the ALERT/THERM2 pin regardless of bit 5 in configuration register 1. 

    Also, I think that the differences between ALERT and THERM are as follows, but is this correct?
    ALERT asserts Low on the violating number of consecutive times , and THERM asserts Low as soon as it violates.

    Figure 18 gives a good explanation. When in THERM mode, the ALERT/THERM2 pin will be triggered when you are above the THERM limit (for 'x' number of reads, determined by the consecutive alert register), and will de-assert only when you fall back below the THERM Hysteresis Value. In ALERT mode, the pin will assert when you are outside the ALERT High or ALERT Low Limits, and releases the line after the MCU performs a read of the status register.

    Essentially, in alert mode you have 2 limits (a hot and cold limit), and in therm mode you have a hot limit, and a hysteresis setting. 

    Best Regards,
    Brandon Fisher