Microchip Technology TSSOP20EV データシート

Signal Chain Design Guide

Many system applications require the measurement of a 

physical or electrical condition, or the presence or absence 

of a known physical, electrical or chemical quantity. Analog 

sensors are typically used to indicate the magnitude or 

change in the environmental condition, by reacting to the 

condition and generating a change in an electrical property 

as a result.
Typical phenomena that are measured are:

   

■

Electrical signal and properties

   

■

Magnetic signal and properties

   

■

Temperature

   

■

Humidity

   

■

Force, weight, torque and pressure

   

■

Motion and vibration

   

■

Flow

   

■

Fluid level and volume

   

■

Light and infrared

   

■

Chemistry/gas

Magnetic

Hall Effect

Voltage

Magneto-Resistive

Resistance

Temperature

Thermocouple

Voltage

RTD

Resistance

Thermistor

Resistance

IC

Voltage

Infrared

Current

Humidity

Capacitive

Capacitance

Infrared

Current

Force, Weight, Torque, Pressure

Strain Gauge

Resistance/Voltage

Load Cell

Resistance

Piezoelectric

Voltage or Charge

Mechanical Transducer

Resistance, Voltage, Capacitance

Motion and Vibration

LVDT

AC Voltage

Piezoelectric

Voltage or Charge

Microphone

Voltage

Ultrosonic

Voltage, Resistive, Current

Accelerometer

Voltage

Flow

Magnetic Flowmeter

Voltage

Mass Flowmeter

Resistance/Voltage

Ultrasound/Doppler

Frequency

Hot-wire Anemometer

Resistance

Mechanical Transducer (turbine)

Voltage

Fluid Level and Volume

Ultrasound

Time Delay

Mechanical Transducer

Resistance/Voltage

Capacitor

Capacitance

Switch

On/Off

Thermal

Voltage

Touch

Capacitance

Voltage

Inductance

Current

Resistance

Frequency

Proximity

Capacitance

Voltage, Frequency

Inductance

Current, Frequency

Resistance

Voltage, Current

Light

Photodiode

Current

Chemical

pH Electrode

Voltage

Solution Conductivity

Resistance/Current

CO Sensor

Voltage or Charge

Photodiode (turbidity, colorimeter)

Current

Ion Sensor

Current

There are sensors that respond to these phenomena by 

producing the following electrical properties:

   

■

Voltage

   

■

Current

   

■

Resistance

   

■

Capacitance

   

■

Charge

This electrical property is then conditioned by an analog 

circuit before being driven to a digital circuit. In this way, 

the environmental condition can be “measured” and the 

system can make decisions based on the result.
The table below provides an overview of typical 

phenomena, the type of sensor commonly used to measure 

the phenomena and electrical output of the sensor.
For additional information, please refer to