THERMOSTAT MODE (TM1/TM0)

POLARITY (POL)

FAULT QUEUE (F1/F0)

TMP122-EP

The Thermostat Mode bits of the TMP122 indicate to the device whether to operate in Comparator Mode,

Interrupt Mode or Interrupt Comparator Mode. For more information on Comparator and Interrupt Mode, see text

HIGH and LOW limit registers. The bit assignments for thermostat mode are described in Table 7. Power on

default is comparator mode.

Table 7. Mode Settings

TM1

TM0

MODE OF OPERATION

0

0

Comparator mode

0

1

Interrupt mode

1

0

Interrupt comparator mode

1

1

Reserved

The Polarity Bit of the TMP122 adjusts the polarity of the ALERT pin output. By default, POL = 0 and the ALERT

pin will be active LOW, as shown in Figure 8. For POL = 1 the ALERT Pin will be active HIGH, and the state of

the ALERT Pin is inverted.

Figure 8. ALERT Output Transfer Function Diagrams

The Fault Queue is provided to prevent a false alert due to environmental noise and requires consecutive fault

measurements to trigger the alert function of the TMP122. Table 8 defines the number of consecutive faults

required to trigger a consecutive alert condition. Power-on default for F1/F0 is 0/0.

Copyright © 2008, Texas Instruments Incorporated

Submit Documentation Feedback

9

Product Folder Link(s): TMP122-EP