Atmel Xplained Pro Evaluation Kit for the ATSAMD21J18A Microcontroller ATSAMD21-XPRO ATSAMD21-XPRO Data Sheet
Product codes
ATSAMD21-XPRO
947
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181C–SAM-D21_Datasheet–07/2014
36.9.8 Temperature Sensor Characteristics
36.9.8.1 Temperature Sensor Characteristics
Table 36-30. Temperature Sensor Characteristics
)
Note:
1. These values are based on characterization. These values are not covered by test limits in production.
36.9.8.2 Software-based Refinement of the Actual Temperature
The temperature sensor behavior is linear but it depends on several parameters such as the internal voltage reference
which itself depends on the temperature. To take this into account, each device contains a Temperature Log row with
data measured and written during the production tests. These calibration values should be read by software to infer the
most accurate temperature readings possible.
which itself depends on the temperature. To take this into account, each device contains a Temperature Log row with
data measured and written during the production tests. These calibration values should be read by software to infer the
most accurate temperature readings possible.
This Software Temperature Log row can be read at address 0x00806030
This section specifies the Temperature Log row content and explains how to refine the temperature sensor output using
the values in the Temperature Log row.
the values in the Temperature Log row.
Temperature Log Row
All values in this row were measured in the following conditions:
z
V
DDIN
= V
DDIO
= V
DDANA
= 3.3V
z
ADC Clock speed = 1MHz
z
ADC mode: Free running mode, ADC averaging mode with 4 averaged samples
z
ADC voltage reference = 1.0V internal reference (INT1V)
z
ADC input = temperature sensor
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Units
I
Temperature sensor output
voltage
voltage
T= 25°C, V
DDANA
= 3.3V
-
0.667
-
V
I
Temperature sensor slope
2.3
2.4
2.5
mV/°C
I
Variation over V
DDANA
voltage
V
DDANA
=1.62V to 3.6V
-1.7
1
3.7
mV/V
Table 36-31. Temperature Log Row Content
Bit Position
Name
Description
7:0
ROOM_TEMP_VAL_INT
Integer part of room temperature in °C
11:8
ROOM_TEMP_VAL_DEC
Decimal part of room temperature
19:12
HOT_TEMP_VAL_INT
Integer part of hot temperature in °C
23:20
HOT_TEMP_VAL_DEC
Decimal part of hot temperature
31:24
ROOM_INT1V_VAL
2’s complement of the internal 1V reference drift at room
temperature (versus a 1.0 centered value)
39:32
HOT_INT1V_VAL
2’s complement of the internal 1V reference drift at hot
temperature (versus a 1.0 centered value)
51:40
ROOM_ADC_VAL
12bit ADC conversion at room temperature
63:52
HOT_ADC_VAL
12bit ADC conversion at hot temperature