ADT7410 Status Register's Tlow and Thigh bits are never set to '!' as expected?

Document created by analog-archivist Employee on Feb 23, 2016
Version 1Show Document
  • View in full screen mode

I am using the ADT7410's Interrupt mode for INT and CT pins, 13 bits
resolution, the ID register is '011' for the revision.

The test is : Ambient temperature is 25°C, with trigger of 27°C, and hysteresis
of 1°C.
The chip is heated.

The interrupt pin is working properly regarding the curve in the datasheet Rev
A(Figure 19 page 21), there are two pulses, one when the temperature goes
higher than the trigger, and the other when the temperature goes lower than the
trigger minus the hysteresis.

However, when I try to read the Status register to confirm if is the high or
the low trigger, I obtain '0' for both. I also try to read the LSB in the
temperature with the same results.

Is this normal and how can this be fixed?


This problem is  observed in interrupt mode because the status register is
cleared if any register is read after the assertion of T_High, T_low, or
T_crit.(see interrupt mode Page 21 of the datasheet.)
While in comparator mode the status register bit will remain high until the
temperature drops below "T_High – T_Hyst".Therefore, can the customer switch to
Comparator mode, which can be enabled by asserting Bit[4] of the configuration