STMicroelectronics AN2648 Application Note Increasing the Resolution of Analog Temperature Sensors

About this manual

The document describes a design flow for connecting the STLM20 temperature sensor to a basic microcontroller with an on-board analog-to-digital converter (ADC) to display temperature. It addresses the issue of coarse resolution caused by the limited voltage range of the sensor output relative to the ADC's full scale.

What's inside

• Introduction
• Temperature-to-output transfer function
• Output voltage range analysis
• Resolution limitations
• Signal amplification and inversion
• Circuit implementation using op-amps

Frequently asked questions

What is the smallest temperature increment the 8-bit ADC can resolve when connected directly to the STLM20 sensor?

The smallest temperature increment the ADC can resolve is 1.68°C.

What is the voltage range of the STLM20 output across its full temperature operating range?

The temperature sensor output varies between 0.87 and 2.33 volts across the temperature range —40° to +85°C.

What gain and offset values are required to transform the STLM20 output for the demonstration board application?

A gain of -10 and an offset of approximately +17.5 V are required.