The TMP 36 series of temperature sensors are pretty handy. This one comes in a tidy TO-92 transistor-like package. Feed it Vcc and ground and you get a precise analog output indicating the temperature in degrees C. The accuracy is pretty good too, being ±2°C over a range of -40° to +125°C.

The output is 10mV per °C, with 25°C reading 750mV. Tie this to your microcontroller’s A2D port, and you are set to go!

Specifications

• 3-Pin TO-92 package
• Analog output
• Operating Temperature: -40C to 125°C
• Operating Supply Voltage: 2.7V – 5V nominal, 5.5V Maximum
• Output can be modified to read °F with 4 resistors and a 1.23V zener
• Use of a 0.1µF bypass capacitor on the Vin line is recommended for best stability