semiconductor sensors
TRANSCRIPT
A Sensor is a device that detects events or changes in quantities and provides
a corresponding output
Operation with reverse bias
Capacitance should be
small
Leakage current should be low
In form of IC’s
Thin silicon wafer
thousands of devices can be fabricated
Most popular are AD590 and LM35
Basic principle
VOLTAGE OUTPUT TEMPERATURE SENSORS
Need a source of power supply
Effective linear output
Low output impedance
CURRENT OUTPUT TEMPERATURE SENSORS
High output impedance
Need a input voltage source
Constant current regulators
DIGITAL OUTPUT TEMPERATURE SENSORS
o Fabricated with analog to digital convertor on an IC chip
o Doesn’t provide a standard digital surfaces
o Cannot be employed with standard measuring devices
RESISTANCE OUTPUT TEMPERATURE SENSORS
Typical semi conductor manufacturing equipment
Offers high tolerance to iron migration
Needs extra care
DIODE TEMPERATURE SENSORS
Uses regular PN junction diode
Very cheap and very efficient
Provides temperature coefficient of around 2.3 mV/°C
a. Absolute Pressure Sensor
b. Differential Pressure Sensor
c. Gauge Pressure Sensor d. Negative pressure sensor
The possibilities of applications of the semiconductor sensors are endless.
Research is still going on, almost all the sensors employ the use of semiconductors,
thus called semiconductor sensors.
From a Remote control television to satellite sensing everything involves semiconductor
sensors
