Measured

Temperature

T

HIGH

T

LOW

Device

ALERTPIN

(ComparatorMode)

POL=0

Device

ALERTPIN

(InterruptMode)

POL=0

Device

ALERTPIN

(ComparatorMode)

POL=1

Device

ALERTPIN

(InterruptMode)

POL=1

Read

Read

Time

Read

TMP75C

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SBOS707B – APRIL 2014 – REVISED AUGUST 2014

7.3.2 Temperature Limits and Alert

the temperature result, and their values are compared to the temperature result on every conversion. The

outcome of the comparison drives the behavior of the ALERT pin, which can operate as a comparator output or

an interrupt, and is set by the TM bit in the Configuration register (Table 6).

In comparator mode (TM = 0, default), the ALERT pin becomes active when the temperature is equal to or

conversions. The difference between the two limits acts as a hysteresis on the comparator output, and a fault

counter prevents false alerts as a result of environmental noise.

In interrupt mode (TM = 1), the ALERT pin becomes active when the temperature equals or exceeds the value in

register occurs. After the ALERT pin is cleared, this pin becomes active again only when temperature falls below

and so on. The ALERT pin is cleared also when the device is placed in shutdown mode (see Shutdown Mode for

shutdown mode description). This action also clears the fault counter memory.

The active state of the ALERT pin is set by the POL bit in the configuration register. When POL = 0 (default), the

ALERT pin is active low. When POL = 1, the ALERT pin is active high. The operation of the ALERT pin in the

various modes is illustrated in Figure 7.

Figure 7. ALERT Pin Modes of Operation

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