TMP112

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SBOS473E – MARCH 2009 – REVISED DECEMBER 2015

Table 2 does not list all temperatures. Use the following rules to obtain the digital data format for a given

temperature or the temperature for a given digital data format.

To convert positive temperatures to a digital data format:

1. Divide the temperature by the resolution

2. Convert the result to binary code with a 12-bit, left-justified format, and MSB = 0 to denote a positive sign.

Example: (50°C) / (0.0625°C / LSB) = 800 = 320h = 0011 0010 0000

To convert a positive digital data format to temperature:

1. Convert the 12-bit, left-justified binary temperature result, with the MSB = 0 to denote a positive sign, to a

decimal number.

2. Multiply the decimal number by the resolution to obtain the positive temperature.

Example: 0011 0010 0000 = 320h = 800 × (0.0625°C / LSB) = 50°C

To convert negative temperatures to a digital data format:

1. Divide the absolute value of the temperature by the resolution, and convert the result to binary code with a

12-bit, left-justified format.

2. Generate the twos complement of the result by complementing the binary number and adding one. Denote a

negative number with MSB = 1.

Example: (|–25°C|) / (0.0625°C / LSB) = 400 = 190h = 0001 1001 0000

Two's complement format: 1110 0110 1111 + 1 = 1110 0111 0000

To convert a negative digital data format to temperature:

1. Generate the twos compliment of the 12-bit, left-justified binary number of the temperature result (with MSB

= 1, denoting negative temperature result) by complementing the binary number and adding one. This

represents the binary number of the absolute value of the temperature.

2. Convert to decimal number and multiply by the resolution to get the absolute temperature, then multiply by

–1 for the negative sign.

Example: 1110 0111 0000 has twos compliment of 0001 1001 0000 = 0001 1000 1111 + 1

Convert to temperature: 0001 1001 0000 = 190h = 400; 400 × (0.0625°C / LSB) = 25°C = (|–25°C|);

(|–25°C|) × (–1) = –25°C

Table 3. 13-Bit Temperature Data Format

TEMPERATURE (°C)

DIGITAL OUTPUT (BINARY)

HEX

150

0 1001 0110 0000

0960

128

0 1000 0000 0000

0800

127.9375

0 0111 1111 1111

07FF

100

0 0110 0100 0000

0640

80

0 0101 0000 0000

0500

75

0 0100 1011 0000

04B0

50

0 0011 0010 0000

0320

25

0 0001 1001 0000

0190

0.25

0 0000 0000 0100

0004

0

0 0000 0000 0000

0000

–0.25

1 1111 1111 1100

1FFC

–25

1 1110 0111 0000

1E70

–55

1 1100 1001 0000

1C90

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