Si1000/1/2/3/4/5
Add R/
W
Function/
Description
D7
D6
D5
D4
D3
D2
D1
D0
POR
Def.
tsrange[1] tsrange[0] entsoffs entstrim tstrim[3]
tstrim[2] vbgtrim[1] vbgtrim[0]
12 R/W
Temperature
20h
Sensor Control
tvoffs[7]
tvoffs[6]
tvoffs[5] tvoffs[4]
tvoffs[3]
tvoffs[2]
tvoffs[1]
tvoffs[0]
13 R/W Temperature Value
Offset
00h
Table 23.7. Temperature Sensor Range
entoff
tsrange[1]
tsrange[0]
Temp. range Unit
Slope
ADC8 LSB
0.5 °C
1 °C
1
1
0
0
1
1
1
0
1
0
1
0
–64 … 64
–64 … 192
0 … 128
°C
°C
°C
°F
°K
8 mV/°C
4 mV/°C
8 mV/°C
4 mV/°F
3 mV/°K
1
0.5 °C
1 °F
1
–40 … 216
0 … 341
0*
1.333 °K
Note: Absolute temperature mode, no temperature shift. This mode is only for test purposes. POR value of
EN_TOFF is 1.
The slope of the temperature sensor is very linear and monotonic. For absolute accuracy better than 10 °C
calibration is necessary. The temperature sensor may be calibrated by setting entsoffs = 1 in “Register
12h. Temperature Sensor Control” and setting the offset with the tvoffs[7:0] bits in “Register 13h. Tempera-
ture Value Offset.” This method adds a positive offset digitally to the ADC value that is read in “Register
11h. ADC Value.” The other method of calibration is to use the tstrim which compensates the analog cir-
cuit. This is done by setting entstrim = 1 and using the tstrim[2:0] bits to offset the temperature in “Register
12h. Temperature Sensor Control.” With this method of calibration, a negative offset may be achieved.
With both methods of calibration better than ±3 °C absolute accuracy may be achieved.
The different ranges for the temperature sensor and ADC8 are demonstrated in Figure 23.22. The value of
the ADC8 may be translated to a temperature reading by ADC8Value x ADC8 LSB + Lowest Temperature
in Temp Range. For instance for a tsrange = 00, Temp = ADC8Value x 0.5 – 64.
Rev. 1.0
273
SILICON [ SILICON ]
