Linear Temperature Sensor (Analog Output Generation) - STMicroelectronics SPC572L series Reference Manual

RM0400
When the temperature threshold detection feature is enabled , the temperature sensor
monitors the internal junction temperature of the chip and asserts a signal if any of the three
specified temperature thresholds are crossed.
•
The low temperature digital output signals if the junction temperature falls below the
low temperature threshold (–40 °C).
•
The high temperature digital output 1 signals if the junction temperature rises above the
first high temperature threshold (150 °C).
•
The high temperature digital output 2 signals if the junction temperature rises above the
second high temperature threshold (165 °C).
The threshold detection circuit is calibrated with respect to the factory-test temperatures: the
low temperature threshold is trimmed to match the cold insertion test temperature
(nominally equal to –40 °C) and the high temperature thresholds are trimmed such that one
of them matches the hot insertion test temperature (nominally equal to 150 °C or 165 °C). In
other words, the thresholds are not trimmed to absolute values of temperature but to the
specific temperatures for which the device is validated during factory test.
Hysteresis is applied whenever outputs transition to a logic level low in order to eliminate
spurious toggling. Digital output behavior is illustrated on
High Temperature
Output 2
High Temperature
Output 1
Low Temperature
Output
38.2.2

Linear temperature sensor (analog output generation)

When analog output generation is enabled, the temperature sensor outputs a voltage
proportional to the internal junction temperature of the chip. This analog voltage signal is
converted into a digital code by an on-chip ADC. The temperature value is obtained from a
Figure 376. Digital output behavior with temperature
Low Temperature
Threshold
DocID027809 Rev 4
Figure
Temperature
High Temperature
Temperature
Threshold 1
Temperature
Temperature Sensor
376.
High Temperature
Threshold 2
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