AN2278 Datasheet, PDF (1/9 Pages) STMicroelectronics – Temperature sensor application using ST LM135

AN2278
Application note
Temperature sensor application
using ST LM135
Introduction
This application note describes how to develop a temperature sensor application using the
ST LM135 temperature sensor. Application development was done on a Raisonance REva
board. The Raisonance REva board is a universal board with several useful features for
application development. It has been designed for quick and easy evaluation of a wide range
of microcontrollers. This application uses the ST72325 microcontroller, which is interfaced to
REva using a daughter board.
The main components required for the development of this application are:
■ ST LM135 temperature sensor
■ ST72325 microcontroller
■ ST24C02 I²C EEPROM
■ ST3232 communication interface
Some of the useful features of the REva board are:
■ Digital and analog I/O evaluation features including on-board LEDs, buttons, switches,
external analog connector, temperature sensor and potentiometer
■ On-board I²C EEPROM and bus extension connector
■ On-board RS232 driver and DB9 connector
■ SPI, CAN and USB connections (depending on the target device)
■ Embedded RLink for in-circuit debugging and in-circuit programming V_DD settings for
1.8 V, 3.3 V, 5 V microcontrollers
■ USB powered, no external power required
Section 1 highlights the important features of the LM135 sensor and explains the
temperature calculation used in the application. Section 2 explains the temperature sensor
management and Section 3 focusses on explaining the application flow. Section 4 gives an
overview of the hardware setup required to implement the application.
September 2007
Rev 3
1/9
www.st.com