1 ECE 4950 – Integrated System Design I ECE INTEGRATED SYSTEMS I Design - General Design Approach Timothy Burg

ECE 495 – Integrated System Design I 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.typos and grammatical errors – Writing a Novel mistakes/article.aspx?key=gsaa

ECE 495 – Integrated System Design I 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.

ECE 495 – Integrated System Design I Design Example – Design Tools are Required 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"Fred Brooks A large programming project that does not use good design techniques is equivalent to a tar pit swallowing everything that enters.

5 ECE 4950 – Integrated System Design I Design Example Identify Need Research Specifications Concepts Design Prototype Testing Retire Maintain Use by Customer(s) Distribute and Sell Manufacture Note: The Design is the end product of the Design Process

6 ECE 4950 – Integrated System Design I 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 ECE 4950 – Integrated System Design I What is an Electrical Design? Enough information to manufacture the system Printed Wiring Board Layout Bill of Material (Parts List) Wiring and Cable Diagram Software Design Circuit Diagram Mechanical Drawings

8 ECE 4950 – Integrated System Design I 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

9 ECE 4950 – Integrated System Design I 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 ECE 4950 – Integrated System Design I Wiring and Cable Diagram – Reminder: Engineers use Standards when useful or required – DIN is an European standard for automobile electric terminal numbers, standardizing almost every contact in an automobile with a number code. standardizing Always know that “30” is a connection to the battery What is an Electrical Design?

11 ECE 4950 – Integrated System Design I 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 ECE 4950 – Integrated System Design I What is an Electrical Design? Bill of Material (Parts List) Board Parts Part Name / DescriptionPart DescriptionDigikey Part#QtySchematic ID LED diode DIODE SCHOTTKY 30V 200MA ND2 5V Pwr Bus Decoupling CAP ELECT 47UF 10V VS SMD PCE3875CT- ND2C13, C1 24V Pwr Bus Decoupling CAP 220UF 35V ELECT FP SMD PCE4444CT- ND3C12, C10, C11 Power conn; board mount CONN HDR 4POS R/A KEY-Y 30GOLDA29446-ND1J5 data conn; board mount CONN HEADER 18POS 2MM R/A GOLDWM18865-ND1J4 pull up/down resistor RES 10K OHM 1/10W 5% 0402 SMDP10KJCT-ND14 R11, R12, R14, R13, R15, R16, R17, R18, R10, R19, R20, R21, R22, R23 current limiting res for 5V LED RES 274 OHM 1/4W 1% 1206 SMDP274FCT-ND2R6, R5 current limiting res for 24V LED RES 1.2K OHM 1/2W 5% 2010 SMD KWCT- ND2R7, R8 red LED LED 3.2X1.6MM 635NM RED CLR SMD ND2 24VRedLED, 5VRedLED green LED LED 3X1.5MM 525NM GN WTR CLR SMD ND2 24VGrnLED, 5VGrnLED

13 ECE 4950 – Integrated System Design I What is an Electrical Design? Mechanical Drawings

14 ECE 4950 – Integrated System Design I What is an Electrical Design? Software Design – Flowcharts – State transition diagrams – Algorithms Cost Estimates

15 ECE 4950 – Integrated System Design I What is an Electrical Design? Prototype

16 ECE 4950 – Integrated System Design I 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 ECE 4950 – Integrated System Design I 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 ECE 4950 – Integrated System Design I Functional Decomposition Design approach wherein a system is iteratively decomposed into smaller and smaller subsystems until component design is reached.

19 ECE 4950 – Integrated System Design I Top-Down Approach Define inputs Define outputs Define function function outputs function inputs N=0 N=1 N=2 outputs function inputs outputs function inputs outputs function inputs

20 ECE 4950 – Integrated System Design I Example – Drawing a House Draw House Draw Body Draw Roof Draw Door Draw Window Rectangle Triangle Rectangle Circle Rectangle Line Transfor mer Rectifier Functional decomposition is used in a number of fields.

21 ECE 4950 – Integrated System Design I Top-Down Approach Level 0 Level 1 Level 2 Modulef(*) Inputs Outputs Functionality f 1 (*) f 2 (*) f (*) y x x y Modulef 1 (*) Inputs Outputs Functionality Modulef 2 (*) Inputs Outputs Functionality Modulef 3 (*) Inputs Outputs Functionality Modulef 4 (*) Inputs Outputs Functionality f 1 (*) x y f 3 (*) f 4 (*)

22 ECE 4950 – Integrated System Design I Example – Audio Amplifier Amplify signal <0.5V peak Volume control, 0 – max volume 50W to 8 Ohm load Powered by 120V, 60Hz AC

23 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 0) ModuleAudio Power Amplifier Inputs-Audio Input Signal: 0.5V peak -Power:120 Volts AC, 60 Hz -User volume control: variable control Outputs-Audio output signal: 20V Peak at 2.5A FunctionalityAmplify the input signal to produce a 50W max. output signal. The amplification should have variable user control. The output volume should be variable between no volume and a max peak volume level.

24 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 1) ModuleBuffer Amplifier Inputs-Audio Input Signal: 0.5V peak -Power: +- 25V DC Outputs-audio output signal: 0.5V peak FunctionalityBuffer the input signal and provide unity voltage gain. It should have an input resistance >1M Ohm and an output resistance <100 Ohms outputsfunction inputs

25 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 1) outputs function inputs ModuleHigh Gain Amplifier Inputs-Audio Input Signal: 0.5V peak -User volume control:variable control -Power: +/- 25V DC Outputs-Audio output signal: 20v peak FunctionalityProvide an adjustable voltage gain, between 1 and 40. It should have an input resistance >100k Ohms and an output resistance <100 Ohm inputs

26 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 1) outputs function inputs ModulePower Supply Inputs-120 V AC rms Outputs-Power: +/- 25VDC with up to 3A of current with regulation of <1% FunctionalityConvert AC wall outlet voltage to positive and negative DC output voltages, and provide enough current to drive all amplifiers

27 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 1) function inputs ModulePower Output Stage Inputs-Audio Input Signal: 20v peak -Power: +/- 25V DC Outputs-Audio output signal: 20v peak at up to 2.5A FunctionalityProvide unity voltage gain with output current as required by a resistive loads of up to 2.5A. It should have an input resistance > 1M Ohm and an output resistance < 1Ohm. outputs

28 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 2) Smoothing Filter Regulator Purchase Purchase ? No -> Another level of decomposition. Inputs Outputs Functionality Module Transformer Inputs Outputs Functionality Module Rectifier Decompose the Power Supply Module

29 ECE 4950 – Integrated System Design I Top-Down Approach Some components may be constrained. May want to incorporate a specific device. Not best for innovation.

30 ECE 4950 – Integrated System Design I Bottom-Up Approach Know that your design must include a specific subsystem or component.

31 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 1) Output power function inputs ModulePower Supply Inputs-120 V AC rms Outputs-Power: +- 12VDC with up to 3A of current with regulation of <1% FunctionalityConvert AC wall outlet voltage to positive and negative DC output voltages, and provide enough current to drive all amplifiers Your company uses the following power supply in ALL designs Will have to define the functionality of the amplifier based on including this device Voltage levels

32 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 1) ModulePower Output Stage Inputs-Audio Input Signal: 20V peak -Power: +- 25V DC Outputs-audio output signal:10V peak at up to 1A FunctionalityProvide unity voltage gain with output current as required by a resistive load of up to 2.5A. It should have an input resistance > 1M Ohm and an output resistance < 1Ohm.

33 ECE 4950 – Integrated System Design I Example – Audio Amplifier (Level 0) ModuleAudio Power Amplifier Inputs-Audio Input Signal: 0.5v peak -Power:120 volts AC rms, 60 Hz -User volume control: variable control Outputs-audio output signal:10VPeak value (not given directly, calculate from power output = 12.5W) FunctionalityAmplify the input signal to produce a 50W max. output signal. The amplification should have variable user control. The output volume should be variable between no volume and a max peak volume level.

34 ECE 4950 – Integrated System Design I 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 ECE 4950 – Integrated System Design I Top-Down vs. Bottom-Up In reality both approaches are used iteratively.

36 ECE 4950 – Integrated System Design I Example – Audio Amplifier Build an audio amplifier using the company’s standard Integrated Buffer Amplifier + Power Supply. Standard Must be Used

37 ECE 4950 – Integrated System Design I Example – Audio Amplifier ModuleAudio Power Amplifier Inputs-Audio Input Signal: 0.5v -Power:120 volts AC, 60 Hz -User volume control: variable control Outputs-audio output signal: ? Peak value (not given directly, calculate from power pain 20V) FunctionalityAmplify the input signal to produce a 50W max. output signal. The amplification should have variable user control. The output volume should be variable between no volume and a max peak volume level.

38 ECE 4950 – Integrated System Design I Example – Audio Amplifier Buffer Amplifier and 10V, 5W DC Supply High Gain Amplifier Power Output Stage Audio Input Signal Power 120VAC Buffered Input 10V DC DC Supply Control Volume Audio Output Signal 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 ECE 4950 – Integrated System Design I 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.