JAJS009M January 2004 – December 2020 TMP175 , TMP75
PRODUCTION DATA
In comparator mode (TM = 0), the ALERT pin of the TMP175 and TMP75 becomes active when the temperature equals or exceeds the value in THIGH 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 TLOW value for the same number of faults.
In interrupt mode (TM = 1), the ALERT pin becomes active when the temperature equals or exceeds THIGH 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 become active again by the temperature falling below TLOW. When the temperature falls below TLOW, 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 THIGH. 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 by returning the device to comparator mode (TM = 0). Changing thermostat mode on the TMP75 will clear existing alert in either mode.
Both operational modes are represented in Figure 7-7. Table 7-11, Table 7-12, Table 7-13, and Table 7-14 describe the format for the THIGH and TLOW registers. The most significant byte is sent first, followed by the least significant byte. Power-up reset values for THIGH and TLOW are:
THIGH = 80 °C and TLOW = 75 °C
The format of the data for THIGH and TLOW is the same as for the Temperature register.
D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
---|---|---|---|---|---|---|---|
H11 | H10 | H9 | H8 | H7 | H6 | H5 | H4 |
D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
---|---|---|---|---|---|---|---|
H3 | H2 | H1 | H0 | 0 | 0 | 0 | 0 |
D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
---|---|---|---|---|---|---|---|
L11 | L10 | L9 | L8 | L7 | L6 | L5 | L4 |
D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
---|---|---|---|---|---|---|---|
L3 | L2 | L1 | L0 | 0 | 0 | 0 | 0 |
All 12 bits for the Temperature, THIGH, and TLOW registers are used in the comparisons for the ALERT function for all converter resolutions. The three LSBs in THIGH and TLOW can affect the ALERT output even if the converter is configured for 9-bit resolution.