Single-chip Temperature Sensor Circuit

Published:2011/5/16 22:04:00 Author:Sharon | Keyword: Single-chip, Temperature Sensor | From:SeekIC

IC LM3911 is a silicon sensor constituted by the operational amplifier and constant voltage circuits. Just adding a small number of external components can form a simple electronic thermometer. There is transistor in the silicon used as sensitive device. Transistor base-emitter voltage changes with temperature. When the temperature rises, the base-emitter voltage is also increased. Temperature obtained from a copper block is delivered to the temperature sensor, in the condition that the copper block is linked to pin 5~8. These pins are internally connected to the temperature sensor. Temperature sensor constant voltage source (6.8V) provides power supply. Signals output from the temperature sensor is added to the input in the same direction with the internal operational amplifier, and its potential inverting input is fixed.Therefore, the potential of the operational amplifier output (Pin 2) is controlled by temperature sensor, with the meter indicating the reading. Integrated chip in the circuit needs current about 3mA, and other 0.5mA current passes through the external circuit. The operating temperature range of temperature sensor is -25 ℃ ~ +85 ℃. That indicates the scope is decided by external circuit parameters.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Measuring_and_Test_Circuit/Single_chip_Temperature_Sensor_Circuit.html

Print this Page | Comments | Reading(3)