πŸ”¬
EIM Academy
  • πŸ‘Welcome to EIM Learning Center
  • Electronics Engineering
    • Electronics Enegineering
    • πŸ‘01-Basic Electricity
      • Before Your First Circuit
      • Measure electricity
      • Electromagnetic Induction
    • πŸ‘02-Electrical Circuits
      • Ohm's Law
      • Series and Parallel Circuits
      • Voltage and Current Divider
      • Watt’s Law
      • Kirchhoff's laws
    • πŸ‘03-Analog Circuits and Semiconductors
    • πŸ‘04-Digital Circuits and FPGA
      • Chapter 3 Code
      • Chapter 4 Code
      • Chapter 5 Code
      • Chapter 6 Code
      • Design for Simulations
    • ✍️05-Engineering Signals and Analog Filters
  • Skill Development
    • πŸ‘01-Breadboarding Skills
      • Tools & Accessories
      • Breadboard Projects
    • πŸ‘‰02-Electronics Soldering
      • Practice Projects
    • ✍️03-Perfboard Prototyping
  • Project-based Learning
    • πŸ‘Green Electrical Energy
    • πŸ‘Smart Traffic Light
      • Board Design
      • STEPico & Micropython
      • STEPFPGA & Verilog
      • Demos
    • ✍️Electronic Pinao with FPGA
    • ✍️Semiconductor Cooler
      • What You'll Learn
      • Technical Docs
      • Project Demo
    • πŸ‘Smart Greenhouse
      • Irrigation System
      • Lighting System
      • Temperature Control System
      • Humidity Control System
    • πŸ‘AI with Hardware
      • Finger Detection
      • LCD control by Hand Gesture
      • Robotic Hand
      • Facial Recognition Security System
      • Common Questions
      • Video Tutorial
  • ✍️Bio-medical Applications
    • Blood Oximeter
    • Electrocardiogram
    • Electromyography
  • Educational Development
    • πŸ‘‰Educational Development
    • Educators' Repository
    • Basic Electronics Lesson Plan
      • Electronics Components
      • Ohm's Law
      • Series & Parallel Circuit
      • Watt's Law
      • Kirchhoff's Law
Powered by GitBook
On this page
  • Tools used in this book
  • Some Filters Introduced in the Book
  • SPICE Simulations
  • Audio File Used in Section 6.2
  • Schematics for the ECG Circuit in Section 6.3

Was this helpful?

  1. Electronics Engineering

05-Engineering Signals and Analog Filters

PreviousDesign for SimulationsNext01-Breadboarding Skills

Last updated 2 months ago

Was this helpful?

Tools used in this book

Though we are starting from fundamental principles and emphasizing manual calculation, it is also beneficial to use tools that can help streamline the design process, and these tools offer powerful, free, and fast solutions.

Some Filters Introduced in the Book

The book introduces several types of filters and explains the concept of transfer functions and their derivation. This process involves analyzing circuit components and applying mathematical techniques like Laplace or Fourier transforms. Understanding transfer functions helps readers gain insight into a filter’s frequency response, which is key to designing and optimizing filters in practical applications.

SPICE Simulations

Contains the LT SPICE simulation files used in the book (from Chapter 3 to Chapter 5)

Feel free to download and use them directly to save you some time. While I do encourage you to create these files by yourself if you are new to this powerful simulation tool.

Audio File Used in Section 6.2

This audio file is used in Section 6.2 of the book as the soundtrack sample to be fed into the filter. You may also use any music of your choice, as long as it is in .WAV format. The recommended length is within 30 seconds, as longer files may cause LT SPICE to take more time for processing.

Schematics for the ECG Circuit in Section 6.3

For educational purposes, the schematics of the four PCB modules that make up the complete ECG circuitry are provided below. Note that certain sections of the circuit, such as the input protection circuit, are not shown here but are part of the overall design. The focus is on the core components.

Instrumentation Amplifier

This instrumentation amplifier with a gain of apprximately 100 is used to amplifier the differential signal between the two electrodes placed across the heart of the patient; IN+ and IN- are attached to the measurment probes and the third probe (common) is connected to the ground

High Pass Filter

This high pass filter is used to suppress the low frequency noise due to DC drifting, breathing and muscle contractions of the patient, while providing an additional gain of ~10 to boost the differential signal. The signal measured at the output is expected to be more "zero centered"

Notch Filter

The notch filter implemented using Multiple Feedback topology removes the 50/60Hz power line noise coupled from surrounding enviroment when the patent's body serves as a big capacitance that captures the power line hum into the circuit

Low Pass Filter

The 3rd order Butterworth low pass filter cleans out higher frequency noises (usually above 150Hz) from the harmonics, EMI and noise on the ground, while maintaining the lower band frequency maximally flat. The output is low impedance output which can be directly connected to next stage circuit for measurement and processing.

✍️
12KB
SPICE Simulations.zip
archive
4MB
soundtrack.wav
Instrumentation amplifier
Cover

A powerful, fast, and free SPICE software to simulate analog circuits

Cover

An online based knowledge engine for fast math & science related computations

Cover

An online based design tool for active filters by Analog Devices

Cover

An online based design tool for passive filters by Marki Microwave

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

Cover

LT SPICE
WolframAlpha
Analog Filter Wizard
Marki Microwave