ADT7301
Temperature Conversion Equations
Positive Temperature = ADC Code(d)/32
Negative Temperature = (ADC Code(d)1 − 16384)/32
TEMPERATURE VALUE REGISTER
The temperature value register is a 14-bit read-only register that
stores the temperature reading from the ADC in 13-bit twos
complement format plus a sign bit. The MSB (DB13) is the sign
bit. The ADC can theoretically measure a 255°C temperature
span. The internal temperature sensor is guaranteed to a low
value limit of −40°C and a high limit of +150°C. The temperature
data format is shown in Table 5, which shows the temperature
measurement range of the device (−40°C to +150°C). The
typical performance curve is shown in Figure 11.
Negative Temperature = (ADC Code(d)2 − 8192)/32
01, 0010, 1100, 0000
75°C
00, 1001, 0110, 0000
Table 5. Temperature Data Format
Temperature
Digital Output DB13 … DB0
11, 1011 0000 0000
11, 1100 0100 0000
11, 1100 1110 0000
11, 1110 1100 0000
11, 1111 1111 1111
00, 0000 0000 0000
00, 0000 0000 0001
00, 0001 0100 0000
00, 0011 0010 0000
00, 0110 0100 0000
00, 1001 0110 0000
00, 1100 1000 0000
00, 1111 1010 0000
01, 0010 1100 0000
00, 0000, 0000, 0001
–0.03125°C
−40°C
−30°C
−25°C
−10°C
−0.03125°C
0°C
+0.03125°C
+10°C
+25°C
+50°C
11, 1111, 1111, 1111
11, 1100, 0100, 0000
TEMPERATURE (°C)
150°C
–40°C
–30°C
11, 1011, 0000, 0000
Figure 13. Temperature-to-Digital Transfer Function
1 ADC code uses all 14 bits of the data byte, including the sign bit.
2 DB13 (the sign bit) is removed from the ADC code.
+75°C
+100°C
+125°C
+150°C
Rev. B | Page 10 of 16
TI [ TEXAS INSTRUMENTS ]
