STMicroelectronics AN1755 Application Note High Resolution Thermometer Using ST7 and NE555

This application note presents a realistic example of a thermometer using an ST7 and an NE555.

Brand: STMicroelectronics
Document type: Application Note
Language: English
Pages: 7
File format: PDF
File size: 78 KB
Published: 07 August, 2012
Updated: 01 October, 2023
MD5 checksum: A6926A5AD2E25419754DE175DA869CA6
PDF: STMicroelectronics AN1755 Application Note High Resolution Thermometer Using ST7 and NE555 PDF

About this manual

The document presents a realistic example of building a precision thermometer by combining an ST7 microcontroller with an NE555 monolithic timing circuit. The NE555 operates in the astable mode, where its frequency is controlled by resistance changes from an NTC thermistor. This frequency and duty cycle are then measured by the ST7 timer.

What's inside

Description of NE555
Astable Operation
Theory of Operation - NE555
Theory of Operation - ST7
Design Parameters
Practical Issues

Frequently asked questions

What components are used in the thermometer design?

The design uses an ST7 microcontroller and an NE555 timer.

How is the frequency of the NE555 controlled?

The frequency is controlled by the resistance changes of a NTC-thermistor.

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