Datasheet

TMP105

SLLS648D –FEBRUARY 2005– REVISED SEPTEMBER 2011

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Table 1. Pointer Register Byte

P7 P6 P5 P4 P3 P2 P1 P0

0 0 0 0 0 0 Register Bits

Table 2. Pointer Addresses of the TMP105

P1 P0 REGISTER

0 0 Temperature Register (Read Only)

0 1 Configuration Register (Read/Write)

1 0 T

LOW

1 1 T

HIGH

TEMPERATURE REGISTER

The Temperature Register of the TMP105 is a 12-bit, read-only register that stores the output of the most recent

conversion. Two bytes must be read to obtain data, and are described in Table 3 and Table 4. Note that byte 1 is

the most significant byte; byte 2 is the least significant byte (sent in this order). The first 12 bits are used to

indicate temperature, with all remaining bits equal to zero. The least significant byte does not have to be read if

that information is not needed. Data format for temperature is summarized in Table 5. Following power-up or

reset, the Temperature Register will read 0°C until the first conversion is complete.

Table 3. Byte 1 of Temperature Register

D7 D6 D5 D4 D3 D2 D1 D0

T11 T10 T9 T8 T7 T6 T5 T4

Table 4. Byte 2 of Temperature Register

D7 D6 D5 D4 D3 D2 D1 D0

T3 T2 T1 T0 0 0 0 0

Table 5. Temperature Data Format

TEMPERATURE (°C) DIGITAL OUTPUT (BINARY) HEX

128 0111 1111 1111 7FF

127.9375 0111 1111 1111 7FF

100 0110 0100 0000 640

80 0101 0000 0000 500

75 0100 1011 0000 4B0

50 0011 0010 0000 320

25 0001 1001 0000 190

0.25 0000 0000 0100 004

0 0000 0000 0000 000

–0.25 1111 1111 1100 FFC

–25 1110 0111 0000 E70

–55 1100 1001 0000 C90

The user can obtain 9, 10, 11, or 12 bits of resolution by addressing the Configuration Register and setting the

resolution bits accordingly. For 9-, 10-, or 11-bit resolution, the most significant bits in the Temperature Register

are used with the unused LSBs set to zero.

Product Folder Link(s): TMP105