7.1 Temperature Data Format
Functional Description (Continued)
Temperature data can be read from the Temperature, Thot
,
7.0 TEMPERATURE MEASUREMENT SYSTEM
Thot , Tos and Tos hyst setpoint registers; and written to the
hyst
The LM80 bandgap type temperature sensor and ADC per-
form 9-bit or a 12-bit two’s-complement conversions of the
temperature. An 8-bit digital comparator is also incorporated
that compares the readings to the user-programmable Hot
and Overtemperature setpoints, and Hysteresis values.
T
hot, Thot hyst, Tos and Tos
setpoint registers. Thot set
hyst
point, Thot hyst set point, Tos set point and Tos hyst tempera-
ture data is represented by an 8-bit, two’s complement word
with an LSB (Least Significant Bit) equal to 1˚C:
Temperature
Digital Output
Binary
Hex
7Dh
19h
01h
00h
FFh
E7h
C9h
+125˚C
+25˚C
+1.0˚C
+0˚C
0111 1101
0001 1001
0000 0001
0000 0000
1111 1111
1110 0111
1100 1001
−1.0˚C
−25˚C
−55˚C
DS100040-20
(Non-Linear Scale for Clarity)
FIGURE 8. 9-bit Temperature-to-Digital Transfer
Function
DS100040-16
(Non-Linear Scale for Clarity)
FIGURE 9. 12-bit Temperature-to-Digital Transfer
Function
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