ADT7301

Rev. B | Page 10 of 16

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.

Table 5. Temperature Data Format

Temperature

Digital Output DB13 … DB0

−40°C

11, 1011 0000 0000

−30°C

11, 1100 0100 0000

−25°C

11, 1100 1110 0000

−10°C

11, 1110 1100 0000

−0.03125°C

11, 1111 1111 1111

0°C

00, 0000 0000 0000

+0.03125°C

00, 0000 0000 0001

+10°C

00, 0001 0100 0000

+25°C

00, 0011 0010 0000

+50°C

00, 0110 0100 0000

+75°C

00, 1001 0110 0000

+100°C

00, 1100 1000 0000

+125°C

00, 1111 1010 0000

+150°C

01, 0010 1100 0000

Temperature Conversion Equations

Positive Temperature = ADC Code(d)/32

Negative Temperature = (ADC Code(d)1 − 16384)/32

Negative Temperature = (ADC Code(d)2 − 8192)/32

–40°C

–0.03125°C

–30°C

11, 1111, 1111, 1111

11, 1100, 0100, 0000

11, 1011, 0000, 0000

TEMPERATURE (°C)

75°C

150°C

01, 0010, 1100, 0000

00, 1001, 0110, 0000

00, 0000, 0000, 0001

Figure 13. Temperature-to-Digital Transfer Function