DS1631/DS1631A/DS1731

7 of 14

provides user access to the temperature register. Bits 3 through 0 of the temperature register are

hardwired to 0. When the device is configured for 12-bit resolution, the 12 MSbs (bits 15 through 4) of

the temperature register contain temperature data. For 11-bit resolution, the 11 MSbs (bits 15 through 5)

of the temperature register contain data, and bit 4 is 0. Likewise, for 10-bit resolution, the 10 MSbs (bits

15 through 6) contain data, and for 9-bit the 9 MSbs (bits 15 through 7) contain data, and all unused LSbs

contain 0s. Table 4 gives examples of 12-bit resolution output data and the corresponding temperatures.

bit 15

bit 14

bit 13

bit 12

bit 11

bit 10

bit 9

bit 8

MS Byte

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

LS Byte

000

0

Table 4. 12-BIT RESOLUTION TEMPERATURE/DATA RELATIONSHIP

TEMPERATURE

(

°C)

DIGITAL OUTPUT

(BINARY)

DIGITAL OUTPUT

(HEX)

+125

0111 1101 0000 0000

7D00h

+25.0625

0001 1001 0001 0000

1910h

+10.125

0000 1010 0010 0000

0A20h

+0.5

0000 0000 1000 0000

0080h

0

0000 0000 0000 0000

0000h

-0.5

1111 1111 1000 0000

FF80h

-10.125

1111 0101 1110 0000

F5E0h

-25.0625

1110 0110 1111 0000

E6F0h

-55

1100 1001 0000 0000

C900h

OPERATION—THERMOSTAT FUNCTION

remains at the updated value until the next conversion completes. When the measured temperature meets

Figure 5). This allows the user to program any amount of hysteresis into the output response. The active

out as 0 (even if 1s are written to these bits), and the converted temperature is compared to the 10 MSbs