Rainbow-electronics DS1621 Bedienungsanleitung PDF herunterladen (Seite 4)

DS1621

4 of 16 102299

TEMPERATURE MEASURING CIRCUITRY Figure 2

TEMPERATURE/DATA RELATIONSHIPS Table 2

TEMPERATURE DIGITAL OUTPUT

(Binary)

DIGITAL OUTPUT

(Hex)

+125°C 01111101 00000000 7B00h

+25°C 00011001 00000000 1900h

+½°C 00000001 00000000 0080h

+0°C 00000000 00000000 0000h

-½°C 11111111 10000000 FF80h

-25°C 11100111 00000000 E700h

-55°C 11001001 00000000 C900h

Since data is transmitted over the 2–wire bus MSB first, temperature data may be written to/read from the

DS1621 as either a single byte (with temperature resolution of 1°C) or as two bytes. The second byte

would contain the value of the least significant (0.5°C) bit of the temperature reading as shown in Table

1. Note that the remaining 7 bits of this byte are set to all "0"s.

Temperature is represented in the DS1621 in terms of a ½°C LSB, yielding the following 9–bit format:

T = -25°C

SLOPE ACCUMULATOR

PRESET COMPARE

LOW TEMPERATURE

COEFFICIENT OSCILLATOR

COUNTER PRESET

TEMPERATURE REGISTER

HIGH TEMPERATURE

COEFFICIENT OSCILLATOR

COUNTER

INC

STOP

SET/CLEAR

LSB

1 1 0 0

1 1

0 0 0 0

0 0

MSB

LSB

1 2 3 4 5 6 7 8 9 ... 15 16

Keine Kommentare

Rainbow-electronics DS1621 Bedienungsanleitung Seite 4