Datasheet

AT30TSE752A/754A/758A [DATASHEET]
Atmel-8854G-DTS-AT30TSE752A-754A-758A-Datasheet_102014
12
5.2.2 Comparator Mode
When the device operates in the Comparator mode, then the ALERT pin goes active if the measured temperature meets
or exceeds the high temperature limit set by the T
HIGH
Limit Register and a valid fault condition exists (the consecutive
number of temperature faults has been reached). The ALERT pin will return to the inactive state after the measured
temperature drops below the T
LOW
Limit Register value the appropriate number of times to create a subsequent valid
fault condition. The ALERT pin only changes state based on the high and low temperature limits and fault conditions;
reading from or writing to any register or putting the device into Shutdown mode will not affect the state of the ALERT pin.
The high temperature limit set by the T
HIGH
Limit Register must be greater than the low temperature limit set by the T
LOW
Limit Register in order for the ALERT pin to activate correctly.
If switching from Interrupt mode to Comparator mode while the ALERT pin is already active, then the ALERT pin will
remain active until the measured temperature is below the T
LOW
Limit Register value the appropriate number of times to
create a valid fault condition.
The ALERT pin will return to the inactive state if the device receives the General Call Reset command. When reset, the
contents of the Nonvolatile Configuration Register will be copied into the Configuration Register; therefore, the device
may or may not return to the Comparator mode depending on the setting of the NVCMP/INT bit in the Nonvolatile
Configuration Register.
Figure 5-2 illustrates both the active high and active low ALERT pin response for a sample temperature profile with the
device configured for the Comparator mode and a fault tolerance queue setting of two.
Figure 5-2. Comparator Mode (Fault Tolerance Queue = 2)
Temperature Measurements/Conversions
T
HIGH
Limit
Temperature
T
LOW
Limit
ALERT
(Active High, POL = 1)
ALERT
(Active Low, POL = 0)