In Comparator Mode (TM = 0), the ALERT pin of the TMP101-Q1 becomes active when the temperature equals or exceeds the value in T_HIGH and generates a consecutive number of faults according to fault bits F1 and F0. The ALERT pin remains active until the temperature falls below the indicated T_LOW value for the same number of faults.

In Interrupt Mode (TM = 1) the ALERT pin becomes active when the temperature equals or exceeds T_HIGH for a consecutive number of fault conditions. The ALERT pin remains active until a read operation of any register occurs or the device successfully responds to the SMBus Alert Response Address. The ALERT pin is also cleared if the device is placed in Shutdown Mode. When the ALERT pin is cleared, it only becomes active again by the temperature falling below TLOW. When the temperature falls below T_LOW, the ALERT pin becomes active and remains active until cleared by a read operation of any register or a successful response to the SMBus Alert Response Address. When the ALERT pin is cleared, the above cycle repeats with the ALERT pin becoming active when the temperature equals or exceeds T_HIGH. The ALERT pin can also be cleared by resetting the device with the General Call Reset command. This action also clears the state of the internal registers in the device, returning the device to Comparator Mode (TM = 0).

Both operational modes are represented in Figure 7-8. Table 7-11, Table 7-12, Table 7-13, and Table 7-14 describe the format for the T_HIGH and T_LOW registers. Power-up reset values for T_HIGH and T_LOW are: T_HIGH = 80°C and T_LOW = 75°C. The format of the data for T_HIGH and T_LOW is the same as for the Temperature Register.

All 12 bits for the Temperature, T_HIGH, and T_LOW registers are used in the comparisons for the ALERT function for all converter resolutions. The three LSBs in T_HIGH and T_LOW can affect the ALERT output even if the converter is configured for 9-bit resolution.