DS1620

Table 3 describes the exact relationship of output data to measured temperature.

.

TEMPERATURE/DATA RELATIONSHIPS Table 3

TEMP

DIGITAL OUTPUT

(Binary)

DIGITAL OUTPUT

(Hex)

+125˚C

0 11111010

00FA

+25˚C

0 00110010

0032h

+½˚C

0 00000001

0001h

+0˚C

0 00000000

0000h

-½˚C

1 11111111

01FFh

-25˚C

1 11001110

01CEh

-55˚C

1 10010010

0192h

Higher resolutions may be obtained by reading the temperature, and truncating the 0.5°C bit (the LSB)

from the read value. This value is TEMP_READ. The value left in the counter may then be read by

issuing a READ COUNTER command. This value is the count remaining (COUNT_REMAIN) after the

gate period has ceased. By loading the value of the slope accumulator into the count register (using the

READ SLOPE command), this value may then be read, yielding the number of counts per degree C

(COUNT_PER_C) at that temperature. The actual temperature may be then be calculated by the user

using the following:

TEMPERATURE=TEMP_READ-0.25 +

C

COUNT_PER_

IN)

COUNT_REMA

-

_C

(COUNT_PER

OPERATION–THERMOSTAT CONTROLS

as a thermostat, as shown in Figure 3. When the DS1620’s temperature meets or exceeds the value stored

DS1620’s measured temperature becomes less than the stored value in the high temperature register, TH.

exceeded, or it can be used as part of a closed loop system to activate a cooling system and deactivate it

when the system temperature returns to tolerance.

boundary has been met or exceeded, or as part of a closed loop system it can be used to activate a heating

system and deactivate it when the system temperature returns to tolerance.

the temperature equals or falls below TL. In this way, any amount of hysteresis can be obtained.

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