TMP708 Resistor Programmable Temperature Switch

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Introduction

To check the temperature at different points, the switch called resistor programmable temperature switch has been designed by the engineers. Basically, it is designed to surpass the use of variable resistors and resistive sensors in the system when testing the device’s temperature. So, in this tutorial, we are going to create a “Resistor Programmable Temperature Switch” using TMP708 IC. The IC has temperature threshold accuracy from ±0.5 to °C to a maximum of ±3°C, that is from 60 degrees to 100 degrees. Further, the quiescent current consumption is about 40 microamperes. The most beneficial element is that this IC requires very few external components to operate. Hence, this makes it more promising and affordable.

Hardware Required

S.no	Component	Value	Qty
1.	IC	TMP708	1
2.	Capacitor	0.1µF	1
3.	Resistor	470KΩ, 30KΩ,150Ω	1, 1, 1
4.	3-Pin Female Connector	–	1

Circuit Diagram

Working Explanation

This Resistor Programmable Temperature Switch incles the TMP708 Ic Pin 5 is for the input power supply while pin 2 is for the ground. Pin 1 is for the analog input set point for the temperature. So, we have connected an external 1% resistor between SET pin 1 and GND pin 2. PIn 4 is digital input for Hysteresis selection, for 10°C, this pin would be connected to the power supply; for 30°C, this pin should be connected to the ground. And, therefore, we have grounded this pin. Check the output at pin 3 of an IC.