DS1631-DS1731 DALLAS [Dallas Semiconductor], DS1631-DS1731 Datasheet - Page 7

• Manufacturer Part Number: DS1631-DS1731
• Description: High-Precision Digital Thermometer and Thermostat
• Manufacturer: DALLAS [Dallas Semiconductor]

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.
Figure 4. TEMPERATURE, T
Table 4. 12-BIT RESOLUTION TEMPERATURE/DATA RELATIONSHIP
OPERATION—THERMOSTAT FUNCTION
The thermostat output (T
between the measured digital temperature and user-defined upper and lower thermostat trip points. T
remains at the updated value until the next conversion completes. When the measured temperature meets
or exceeds the value stored in the upper trip-point register (T
until the measured temperature falls below the value stored in the lower trip-point register (T
Figure 5). This allows the user to program any amount of hysteresis into the output response. The active
state of T
The user-defined values in the T
with the MSb (bit 15) containing the sign bit (S). The T
R1 bits in the configuration register (see Table 6), so the T
temperature resolution. For example, for 10-bit resolution bits 5 through 0 of the T
out as 0 (even if 1s are written to these bits), and the converted temperature is compared to the 10 MSbs
of T
The T
device installation. Writing to and reading from the T
MS Byte
LS Byte
H
and T
H
and T
OUT
L
.
is user-programmable through the polarity bit (POL) in the configuration register.
L
registers are stored in EEPROM; therefore, they are NV and can be programmed prior to
bit 15
TEMPERATURE
bit 7
2
S
-1
+25.0625
-25.0625
+10.125
-10.125
+125
(°C)
+0.5
-0.5
-55
0
OUT
bit 14
bit 6
2
2
) is updated after every temperature conversion, based on a comparison
-2
6
H
and T
H
, AND T
bit 13
bit 5
DIGITAL OUTPUT
0111 1101 0000 0000
0001 1001 0001 0000
0000 1010 0010 0000
0000 0000 1000 0000
0000 0000 0000 0000
1111 1111 1000 0000
1111 0101 1110 0000
1110 0110 1111 0000
1100 1001 0000 0000
2
2
L
-3
5
registers (see Figure 4) must be in two’s complement format
(BINARY)
7 of 14
L
bit 12
REGISTER FORMAT
bit 4
2
2
-4
H
4
and T
H
and T
H
L
), T
registers is achieved using the Access TH
bit 11
H
bit 3
L
2
0
3
resolution is determined by the R0 and
and T
OUT
DIGITAL OUTPUT
becomes active and remains active
L
resolution matches the output
(HEX)
7D00h
0A20h
F5E0h
E6F0h
C900h
FF80h
1910h
0080h
0000h
bit 10
bit 2
2
0
2
DS1631/DS1631A/DS1731
H
and T
bit 9
bit 1
2
0
1
L
registers read
L
) (see
bit 8
bit 0
2
0
0
OUT