Although it is simple to measure temperature in a
stand-alone system without the help of Microchip’s Pro-
grammable Gain Amplifiers (PGA), a variety of prob-
lems can be eliminated by implementing temperature-
sensing capability in multiplexed applications with a
PGA. One of the main advantages is that you can elim-
inate a second signal path to the microcontroller and
still maintain the accuracy of your sensing system. In
particular, the multiplexed PGAs you can use are the
MCP6S22 (two-channel), MCP6S26 (six-channel), and
MCP6S28 (eight-channel).
The most common sensors for temperature measure-
ments are the Thermistor, Silicon Temperature Sensor,
RTD and Thermocouple. Microchip’s PGAs are best
suited to interface to the Thermistor or Silicon
Temperature Sensor.
In this application note we will discuss the implementa-
tion of temperature measurement systems from sensor
to the PICmicro
®
microcontroller using a NTC Ther-
mistor, Silicon Temperature sensor, PGA, anti-aliasing
filter, A/D converter and microcontroller.M AN867
Temperature Sensing With A Programmable Gain Amplifier
Author: Bonnie C. Baker
Microchip Technology Inc. 10000000
NTC Thermistor Resistance ()
10 k @ 25C thermistor
1000000
INTRODUCTION
100000
Although it is simple to measure tempera……
