7.3.1 Temperature Measurement Data

The local and remote temperature sensors have a resolution of 12 bits (0.0625°C). Temperature data that result from conversions within the default measurement range are represented in binary form, as shown in the Standard Binary column of Table 2. Any temperatures above 127°C result in a value that rails to 127.9375 (7FFh). The device can be set to measure over an extended temperature range by changing bit 2 (RANGE) of the configuration register from low to high. The change in measurement range and data format from standard binary to extended binary occurs at the next temperature conversion. For data captured in the extended temperature range configuration, an offset of 64 (40h) is added to the standard binary value, as shown in the Extended Binary column of Table 2. This configuration allows measurement of temperatures as low as –64°C, and as high as 191°C; however, most temperature-sensing diodes only operate within the range of –55°C to 150°C. Additionally, the TMP461-SP is specified only for ambient temperatures ranging from –55°C to 125°C; parameters in the Absolute Maximum Ratings table must be observed.

Both local and remote temperature data use two bytes for data storage. The high byte stores the temperature with 1°C resolution. The second or low byte stores the decimal fraction value of the temperature and allows a higher measurement resolution, as shown in Table 3. The measurement resolution for both the local and the remote channels is 0.0625°C.