CC2520 datasheet(21/133 Pages) TI

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CC2520 DATASHEET

2.4 GHZ IEEE 802.15.4/ZIGBEE® RF TRANSCEIVER

SWRS068 – DECEMBER 2007

WWW.TI.COM

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

Min

Typ

Max

Unit

Temp sensor voltage at 25°C

0.8

Temp. sens. output vs temperature

mV/10°C

Temp. sens. output vs supply voltage

mV/V

Temp. sens accuracy no calibration (at fixed voltage)

+/-12

°C

Temp, sens. accuracy with 1-point calibration (at fixed voltage)

+/-1

°C

CC2520 Datasheet(PDF) 21 Page - Texas Instruments