AN4504 datasheet(39/41 Pages) STMICROELECTRONICS

Part #	AN4504

Description	This document is intended to provide usage information

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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AN4504

Temperature sensor

The L3G4200D is provided with an internal temperature sensor that is suitable for delta

temperature measurement. Temperature data are generated with a frequency of 1 Hz and

are stored inside the OUT_TEMP register in two’s complement format with a sensitivity

of -1 LSB/°C.

7.1

Example of delta temperature data calculation

In Table 33 we show an example of the content of OUT_TEMP. We select the content of the

OUT_TEMP register in two different moments, t1 and t2 and we calculate the temperature

delta between moment t1 and moment t2.

We can calculate temperature shift as:

DeltaT = OUT_TEMP@t2 – OUT_TEMP@t1 = -5 LSB.

Using the sensitivity information we get:

DeltaT = -5 LSB * -1°C/LSB = +5 °C.

Table 33. OUT_TEMP register content

OUT_TEMP

Time

binary

hex

00000100

00000011

00000010

00000001

00000000

00001111

-1

00001110

-2

00001101

-3

00001100

-4

AN4504 Datasheet(PDF) 39 Page - STMicroelectronics