DS1626/DS1726

7 of 13

Table 4. 12-BIT RESOLUTION TEMPERATURE/DATA RELATIONSHIP

TEMPERATURE

(

°C)

DIGITAL OUTPUT

(BINARY)

DIGITAL OUTPUT

(HEX)

+125

0111 1101 0000

7D0h

+25.0625

0001 1001 0001

191h

+10.125

0000 1010 0010

0A2h

+0.5

0000 0000 1000

008h

0

0000 0000 0000

000h

-0.5

1111 1111 1000

FF8h

-10.125

1111 0101 1110

F5Eh

-25.0625

1110 0110 1111

E6Fh

-55

1100 1001 0000

C90h

OPERATION—THERMOSTAT FUNCTION

defined two’s complement values. The MSb (bit 11) of each register contains the two’s complement

those bits. The unused LSbs are determined by the conversion resolution set by R1 and R0 in the

configuration register. Therefore, for 9-bit conversions bits 2 through 0 will be 0, for 10-bit

conversions bit 1 and bit 0 will be 0, and for 11-bit conversions bit 0 will be 0. All bits are used for 12-

bit conversions, so no bits are forced to 0. However, regardless of the conversion resolution, when

received 12 bits, so if the operation is terminated before 12 bits have been received, the data will be

lost. Any additional bits sent after the first twelve are ignored (e.g., if two 8-bit words are written).

Another DS1626/DS1726 thermostat feature is the temperature-high flag (THF) and temperature-low

flag (TLF) in the configuration register. These bits provide a record of whether the temperature has

the TLF bit in the configuration register will be set to 1. Once THF and/or TLF has been set, it will

remain set until the user overwrites it with a 0 or until the power is cycled.