CC2520_11 Datasheet, PDF (21/133 Pages) Texas Instruments – 2.4 GHZ IEEE 802.15.4/ZIGBEE RF TRANSCEIVER

CC2520 DATASHEET
2.4 GHZ IEEE 802.15.4/ZIGBEE® RF TRANSCEIVER
SWRS068 – DECEMBER 2007
5.11.1 Using the Temperature Sensor
The on-chip temperature sensor can be accessed via the GPIO0 and GPIO1 pins by following this procedure:
• Configure GPIO0 and GPIO1 as inputs by writing 0x80 to the GPIOCTRL0 and GPIOCTRL1 registers.
• Enable analog output functionality for these two pins by setting GPIOCTRL.GPIO_ACTRL=’1’.
• Select temperature sensor output by writing 0x01 to the ATEST register. This will make GPIO1 output
GND and GPIO0 will output a voltage proportional to the temperature.
• Use an ADC in the microcontroller to measure the output voltage on GPIO0 and then calculate the
temperature.
The output from the temperature sensor is shown in graph form in section 5.9, but as a basis for calculating
the temperature, the following numbers can be used:
Tc=-40 – 125°C, VDD=1.8 – 3.8 V
Parameter
Temp sensor voltage at 25°C
Temp. sens. output vs temperature
Temp. sens. output vs supply voltage
Temp. sens accuracy no calibration (at fixed voltage)
Temp, sens. accuracy with 1-point calibration (at fixed voltage)
Min
Typ
Max
Unit
0.8
V
25
mV/10°C
6
mV/V
+/-12
°C
+/-1
°C
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