JAJSNM5A December 2021 – August 2022 TMP9R00-SP
PRODUCTION DATA
The TMP9R00-SP device allows for a different η-factor value to be used for converting remote channel measurements to temperature for each temperature channel. There are eight η-Factor Correction registers assigned: one to each of the remote input channels (addresses 41h, 49h, 51h, 59h, 61h, 69h, 71h and 79h). Each remote channel uses sequential current excitation to extract a differential VBE voltage measurement to determine the temperature of the remote transistor. Equation 1 shows this voltage and temperature.
The value η in Equation 1 is a characteristic of the particular transistor used for the remote channel. The POR value for the TMP9R00-SP device is η = 1.008. The value in the η-Factor Correction register can be used to adjust the effective η-factor, according to Equation 2 and Equation 3.
The η-factor correction value must be stored in a two's-complement format, which yields an effective data range from –128 to +127. The POR value for each register is 0000h, which does not affect register values unless a different value is written to the register. The resolution of the η-factor register changes linearly as the code changes and has a range from 0.0004292 to 0.0005476, with an average of 0.0004848.
NADJUST ONLY BITS 15 TO 8 IN THE REGISTER ARE SHOWN | η | ||
---|---|---|---|
BINARY | HEX | DECIMAL | |
0111 1111 | 7F | 127 | 0.950205 |
0000 1010 | 0A | 10 | 1.003195 |
0000 1000 | 08 | 8 | 1.004153 |
0000 0110 | 06 | 6 | 1.005112 |
0000 0100 | 04 | 4 | 1.006073 |
0000 0010 | 02 | 2 | 1.007035 |
0000 0001 | 01 | 1 | 1.007517 |
0000 0000 | 00 | 0 | 1.008 |
1111 1111 | FF | –1 | 1.008483 |
1111 1110 | FE | –2 | 1.008966 |
1111 1100 | FC | –4 | 1.009935 |
1111 1010 | FA | –6 | 1.010905 |
1111 1000 | F8 | –8 | 1.011877 |
1111 0110 | F6 | –10 | 1.012851 |
1000 0000 | 80 | –128 | 1.073829 |