1. Biomedical Instruments Design 475 BMIS Circuit Design

2. Introduction  A support is used to hold all the parts of the circuit  An electronic circuit contains many elements  Components  Wires (Connexions)  A board  A Breadboard

3. Electronic Circuit representation  What are the differences between the two representations of the circuit?  How many components are there in each representation?  How many nodes are there in each representation?

4.  Graphical elements are needed in order to draw circuits  An electronic circuit can be represented in many ways  Schematic  Printed Circuit Board (PCB)  Symbols  Footprints The same components are drawn differently in each type of representation Electronic Circuit representation

5.  To convert a schematic into a printed circuit board we need:  The pin configuration of each component  The footprint of each component  The value of the current in the circuit’s nodes  The desired dimensions of the final circuit

6. Pin Configuration  Example 1 The pin configuration of a transistor

7. Pin Configuration  Example 2 The pin configuration of an IC DIL8 SO8

8. Copper tracks design (PCB)  Question Why there are different widths of the copper tracks in the same PCB? Different current value Different track width

9. Exercise  Using DIL8 footprint for IC1, draw a PCB for this circuit?  How many components are there in this circuit?  How many nodes are there in each representation?