Datasheet
The temperature reading is in °C using a 16-bit sign-
extended two’s complement format. Table 1 shows
examples of temperature and the corresponding data
for 12-bit resolution. With two’s complement, the sign
bit(s) is set if the value is negative. If the device is con-
figured for 12-bit resolution, all bits in the LS byte are
valid; for a reduced resolution, bit 0 (11-bit mode), bits
0 to 1 (10-bit mode), and bits 0 to 2 (9-bit mode) are
undefined.
The result of a temperature conversion is automatically
compared to the values in the alarm registers to deter-
mine whether an alarm condition exists. Alarm thresh-
olds are represented as two’s complement number.
With 8 bits available for sign and value, alarm thresh-
olds can be set in increments of 1°C. An alarm condi-
tion exists if a temperature conversion results in a value
that is either higher than or equal to the value stored
in the TH register or lower than or equal to the value
stored in the TL register. If a temperature alarm condi-
tion exists, the device responds to the Conditional
Search ROM command. The alarm condition is cleared
if a subsequent temperature conversion results in a
temperature reading within the boundaries defined by
the data in the TH and TL registers.
1-Wire Digital Thermometer with
Sequence Detect and PIO
DS28EA00
8 Maxim Integrated
ADDRRESS BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
0h 2
3
2
2
2
1
2
0
2
-1
2
-2
2
-3
2
-4
LS BYTE
1h S S S S S 2
6
2
5
2
4
MS BYTE
TEMPERATURE
(°C)
DIGITAL OUTPUT
(BINARY)
DIGITAL OUTPUT
(HEX)
+85* 0000 0101 0101 0000 0550h
+25.0625 0000 0001 1001 0001 0191h
+10.125 0000 0000 1010 0010 00A2h
+0.5 0000 0000 0000 1000 0008h
0 0000 0000 0000 0000 0000h
-0.5 1111 1111 1111 1000 FFF8h
-10.125 1111 1111 0101 1110 FF5Eh
-25.0625 1111 1110 0110 1111 FE6Fh
-40 1111 1101 1000 0000 FD80h
Table 1. Temperature/Data Relationship
*
The power-on reset value of the Temperature Readout register is +85°C.
ADDRRESS BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
2h S 2
6
2
5
2
4
2
3
2
2
2
1
2
0
HIGH ALARM (TH)
3h S 2
6
2
5
2
4
2
3
2
2
2
1
2
0
LOW ALARM (TL)
Register Detailed Descriptions
Temperature Readout Register Bitmap
Temperature Alarm Registers Bitmap