1°C Triple Temperature Sensor with Beta Compensation and Hotter of Two Zones
Datasheet
3.5
Temperature Measurement Results and Data
Each temperature result for each zone is available in two byte wide data registers. As shown in
Section 4.1, the 11-bit format has the 8 most significant bits stored in the high byte register and the 3
least significant bits stored in the three MSB positions of the low byte register. The delta-sigma ADC
may be operated with more than 11 bits of resolution for improved averaging as described in
Section 4.5, but the temperature result is reported at 11-bit resolution.
The temperature results for the two remote zones are also stored in extended format with a range from
-64°C to +191°C. The data format is a 2’s complement number offset by 64°C as shown in Section 4.2.
The data for each of the remote zones in both legacy and extended format is stored in separate data
registers so that both data formats are always available. Table 3.2 shows the default and extended
range formats.
Table 3.2 EMC1043 Temperature Data Format
RANGE -64°C TO 127°C
BINARY
RANGE -64°C TO 191°C
OFFSET BINARY
TEMPERATURE (°C)
Diode Fault
100 0000 0000
100 0000 0000
<= -64
-63.875
-63
110 0000 0000
110 0000 0001
110 0000 1000
111 1111 1000
000 0000 0000
000 0000 0001
000 0000 1000
010 0000 0000
010 0000 1000
011 1111 1000
011 1111 1111
011 1111 1111
011 1111 1111
011 1111 1111
100 0000 0000
100 0000 0001
100 0000 1000
101 1111 1000
110 0000 0000
110 0000 0001
110 0000 1000
000 0000 0000
000 0000 1000
001 1111 1000
001 1111 1111
010 0000 0000
011 1111 1000
011 1111 1111
-1
0
0.125
1
64
65
127
127.875
128
191
>= 191.875
3.6
Resistance Error Correction (REC)
Resistance error correction is an automatic feature that eliminates the need to characterize and
compensate for series resistance in the external diode lines. The EMC1043 corrects for as much as
100 ohms of series resistance.
When using a temperature sensor that does not include resistance error correction, voltage developed
across the parasitic resistance in the external diode path produces an error in the reported
temperature. The error introduced by this resistance is approximately +0.7°C per ohm. Sources of
series resistance are PCB trace resistance, on die (i.e. on the processor) metal resistance, bulk
resistance in the base and emitter of the temperature transistor.
SMSC EMC1043
Revision 1.37 (09-05-06)
DATA1S5HEET
SMSC [ SMSC CORPORATION ]
