High Limit

Low Limit

Time

Measured

Temperature

FHx

FLx (Always 0)

Configuration and Temperature

Register Reads

ALERTx Pin

Global Alert Clear x Command

TMP107

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SBOS716B – MAY 2015 – REVISED SEPTEMBER 2015

In therm mode (Tx/Ax = 1), the high and low limits are used to form an upper-limit threshold detector. If the

temperature result exceeds the high limit, the FHx flag and the ALERTx pin are asserted. The FHx flag and the

ALERTx pin are then deasserted only after the temperature falls below the low limit. In therm mode, only the FHx

flag is active. The FLx flag always reads 0. In therm mode, ALERTx and the flags are asserted and deasserted

only at the end of a conversion and cannot be cleared by a configuration register read or global alert clear x

command. Figure 17 shows therm-mode operation.

Figure 17. ALERTx Pin Behavior in Therm Mode (POLx = 0)

The limit registers default values are programmed in the EEPROM, and are acquired during power up or reset.

The values can be dynamically changed by writing to the register. Disable alert and flag functionality by

programming the high limit register to the highest temperature (7FFCh) and the low limit register to the lowest

temperature (8000h). When disabled, the alert pins can still be controlled by polarity bits POL1 and POL2 (bit 7

and bit 3, respectively, in the configuration register) so that they work like general-purpose outputs (GPOs).

7.3.2.1 ALERT1, ALERT2, R1, and R2 Pins

ALERT1 and ALERT2 are open-drain output pins that require pullup resistors to operate properly. The TMP107

contains internal 100-k

Ω pullup resistors connected between pins ALERT1 and R1, and pins ALERT2 and R2.

To use the internal pullup resistors, connect pins R1 and R2 to V+, or to a voltage suitable for use with pullup

resistors in the system. If external pullup resistors are used, float pins R1 and R2.

Copyright © 2015, Texas Instruments Incorporated

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