EC302 – Electronic Computer Aided Design

MOHD AT-TARMIZI BIN ABU HASSAN

013-3507201

FIRST WARNING !!!

• NO excuse for who come late to my class• NO reconsider for any marks given• NO empty-talk in my class• NO delay assignments submitting• NO inappropriate wear• NO hang around in my class• NO stupid talk

THE INTRODUCTION

CAD = Computer Aided Design

• modeling of physical systems on computers

• allowing both interactive and automatic analysis of design variants

• expression of designs in a form suitable for manufacturing

* Also known as CADD (Computer Aided Design & Drafting)

Software

• Altium Designer a.k.a DXP Designer• PSpice• PLECS• Crocodile Clips a.k.a Crocodile Technology• LiveWire• Eagle DXFmany more….

Type of Simulation Circuit

• Analog• Digital• Mixed-signal

Type of Simulation

• DC Analysis• DC Sweep Analysis• AC Analysis• Transfer Function Analysis• Transient Analysis

DC Analysis

• Determination of steady-state response of the circuit when time-invariant DC sources are applied.

DC Sweep Analysis

• Determination of response of the circuit when excitation, or any other component is varied over a range.

AC Analysis

• a.k.a Frequency Domain Analysis • Determination of steady-state response of

the circuit when sinusoidal excitation is applied mine the frequency response of the circuit.

• The frequency of excitation can be varied to determine the frequency response of the circuit.

Transfer Function Analysis

• Determination of small-signal transfer function with small-signal gain, input impedance, output impedance.

Transient Analysis

• a.k.a Time Domain Analysis• Determination of variation of response of

the circuit with respect to time.

Advantages of Simulation

• able to provide users with practical feedback when designing real world systems

• study a problem at several different levels of abstraction

• can be used as an effective means for teaching or demonstrating concepts to students

Disadvantages of Simulation

• computationally intensive processing required by some simulators

• restricted by limited hardware platforms which cannot meet the computational demands of the simulator

• introduce simplifying assumptions or heuristics into the simulator engine

• computational complexity is to employ the hierarchical approach to design and simulation

Simulation Method

• Circuit level• Logic level• System level

Design and Simulation Process

Identify Project

Design / Redesign Project

Simulation

Testing

PCB Design Layout

Prototype

- A project or circuit to be designed is identified

- The project/circuit is designed based on theory

- The project designed is simulated using software

package to produce results/outputs of the project operation

- The printed project/circuit board layout is designed and produced

- An actual working model of the project is constructed

- See whether the project actually works as in simulation

Fai

l

Netlist

• Source Element• Passive Device Element• Active Device Element

Source element

• The sources functions to supply the circuit with power supply or input waveforms. There are THREE (3) different types of sources used in simulation

- DC Source

- AC Source

- Transient Source

DC Source

• A source that generates dc voltage and dc current

• There are two types of dc sources: – dependent source– independent source

AC Source

• A source that generates sinusoidal waveforms at different frequencies with the same magnitude

Transient Source

• A source that generates waveform whose amplitude changes with time

• Examples of transient sources are:

- Sine Waveform

- Pulse Waveform

- Polynomial Waveform

- Exponential Waveform

Passive Device Element

• Passive elements are electronic passive components

• Example:

- Resistor

- Capacitor

- Inductor

- Transformer

Active Device Element

• Active device elements are electronic components made of semiconductor material

• Examples :

- Diode

- Bipolar Transistor (BJT)

- Field-Effect Transistor (FET)

- Integrated Circuit (IC)

Why do we need to simulate

• A simulation is not used to figure out how a circuit works

• It is important to know the theory of your design before you simulate

Why do we need to simulate

• In the verification process, results generated by the simulation package will give information about the designed circuit

Output in verification process

• Circuit Output - voltage distribution, current flow, waveforms, frequency response curve, switching speed in digital circuits

• circuit operation sensitivity towards change in other component values

• change in circuit characteristics due to temperature change

• circuit elements parameters could be modify for optimum operation

UNDERSTAND ?

QUIZ 1

• Give at least FOUR (4) types of simulation.

• Draw the flow chart for simulation process.

P/S : Don’t forget to write down your name, reg. no, i/c no, class, and assessment no.

LAST WARNING !!!

• NO excuse for who come late to my class• NO reconsider for any marks given• NO empty-talk in my class• NO delay assignments submitting• NO inappropriate wear• NO hang around in my class• NO stupid talk