ECE 4950 - INTEGRATED SYSTEMS I

1. ECE 4950 - INTEGRATED SYSTEMS I Design - General Design Approach Timothy Burg

2. Career Note: Communication Skills are Important • Cover Letter Mistakes - some employers don't bother reading cover letters, most do. • Using the Wrong Cover Letter Format • Include the date, the recipient's mailing address and your address. • Not Proofing for Typos and Grammatical Errors • Employers tend to view typos and grammatical errors as evidence of your carelessness and inability to write. Proofread every letter you send. • Writing a Novel http://career-advice.monster.com/resumes-cover-letters/cover-letter-tips/avoid-7-killer-cover-letter-mistakes/article.aspx?key=gsaa

3. Career Note: Communication Skills are Important • Making Unsupported Claims • Too many cover letters from college students and recent grads say the applicant has "strong written and verbal communication skills." Without evidence, it's an empty boast. Give some examples for each claim you make. Employers need proof. • Not Sending a Real Cover Letter • Some job seekers type up a one or two-sentence "here's my resume" cover letter, while others attach handwritten letters or sticky notes. These same basic concepts apply to your technical writing! You need to show that you care about your work and are competent. The reason I have you write so much in ECE495 is 1) so you can practice writing and 2) it is required to document your project.

4. Design Example – Design Tools are Required A large programming project that does not use good design techniques is equivalent to a tar pit swallowing everything that enters. The Mythical Man-Month: Essays on Software Engineering(1982) by Fred Brooks, whose central theme is that "adding manpower to a late software project makes it later"

5. Design Example Identify Need Retire Research Maintain Specifications Use by Customer(s) Concepts Distribute and Sell Design Note: The Design is the end product of the Design Process Manufacture Prototype Testing

6. Outline: Design Tools • What is an Electrical Design? • A group of components connected together to perform a function. • Functional Decomposition • Top-down approach • Bottom-up approach

7. What is an Electrical Design? Circuit Diagram Printed Wiring Board Layout Bill of Material (Parts List) Enough information to manufacture the system Software Design Wiring and Cable Diagram Mechanical Drawings

8. What is an Electrical Design? • Schematic or Circuit Diagram • Simplified drawing • Symbols to represent components • Connections between the components that determine functionality Enough information to analyze and predict circuit behavior http://en.wikipedia.org/wiki/Circuit_diagram

9. What is an Electrical Design? • Wiring and Cable Diagram • Wiring on the components and between components • Type of wire, color coding, methods of wire termination, and methods of wire and cable clamping

10. What is an Electrical Design? • Wiring and Cable Diagram • Reminder: Engineers use Standards when useful or required • DIN 72552 is an European standard for automobile electric terminal numbers, standardizing almost every contact in an automobile with a number code. Always know that “30” is a connection to the battery

11. What is an Electrical Design? • Printed Wiring Board (PWB)/Printed Circuit Board (PCB) Layout • Physical arrangement of components and wiring on a printed circuit board

12. What is an Electrical Design? • Bill of Material (Parts List)

13. What is an Electrical Design? • Mechanical Drawings

14. What is an Electrical Design? • Software Design • Flowcharts • State transition diagrams • Algorithms • Cost Estimates

15. What is an Electrical Design? • Prototype

16. What is an Electrical Design? • The product at the end of this class is an Electrical Design: • Schematic or Circuit Diagram • Wiring and Cable Diagram • Printed Circuit Board (PCB) Layout • Bill of Material (Parts List) • Mechanical Drawings • Software Flowcharts, State transition diagrams, Algorithms • Cost Estimates • Working Prototype

17. Design Tools • Need to turn a Technical Concept into an Engineering Solution that satisfies the Requirements • Functional Decomposition • Top-down approach • Bottom-up approach

18. Functional Decomposition • Design approach wherein a system is iteratively decomposed into smaller and smaller subsystems until component design is reached.

19. Top-Down Approach Define function Define outputs Define inputs N=0 function function N=1 inputs outputs outputs inputs function outputs function inputs function N=2 inputs inputs outputs outputs

20. Example – Drawing a House Functional decomposition is used in a number of fields. • Draw House • Draw Body Draw Roof Draw Door Draw Window • Rectangle Triangle • Rectangle Circle Rectangle Line Transformer Rectifier www.cs.washington.edu/education/online/cse142/slides/l-decomposition.ppt

21. Top-Down Approach Level 0 x x x y f(*) Level 1 y f1(*) f2(*) Level 2 y f1(*) f3(*) f4(*)

22. Example – Audio Amplifier • Amplify signal <0.5V peak • Volume control, 0 – max volume • 50W to 8 Ohm load • Powered by 120V, 60Hz AC

23. Example – Audio Amplifier (Level 0)

24. Example – Audio Amplifier (Level 1) inputs function outputs

25. Example – Audio Amplifier (Level 1) inputs outputs inputs function inputs

26. Example – Audio Amplifier (Level 1) outputs function inputs

27. Example – Audio Amplifier (Level 1) function inputs outputs

28. Transformer Module Inputs Outputs Functionality Rectifier Module Inputs Outputs Functionality Example – Audio Amplifier (Level 2) • Decompose the Power Supply Module Purchase Purchase Purchase Purchase ? No -> Another level of decomposition. Smoothing Filter Regulator

29. Top-Down Approach • Some components may be constrained. • May want to incorporate a specific device. • Not best for innovation.

30. Bottom-Up Approach Know that your design must include a specific subsystem or component.

31. Example – Audio Amplifier (Level 1) Output power Voltage levels function inputs Your company uses the following power supply in ALL designs Will have to define the functionality of the amplifier based on including this device

32. Example – Audio Amplifier (Level 1)

33. Example – Audio Amplifier (Level 0)

34. Bottom-Up Approach • Facilitates use of standard or reusable components. • Lego approach – I have all of these pieces, what can I build with the components I have?

35. Top-Down vs. Bottom-Up • In reality both approaches are used iteratively.

36. Example – Audio Amplifier • Build an audio amplifier using the company’s standard Integrated Buffer Amplifier + Power Supply. Standard Must be Used

37. Example – Audio Amplifier

38. Example – Audio Amplifier Control Volume Buffer Amplifier and 10V, 5W DC Supply High Gain Amplifier Power Output Stage Audio Output Signal Buffered Input Audio Input Signal 10V DC Power 120VAC DC Supply This DC Supply is probably not the same as the one specified through the top-down approach. Continue the rest of the design using a top-down design approach.

39. Summary • Many tools available for organizing your design. • Size of the project will determine what tools are useful. • Key point: Before starting a design project identify the tools that are appropriate for your project.