The Design Process Applying Value Analysis to Determine an Optimum Solution
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The Design Process The Design Process Applying Value Applying Value Analysis to Determine Analysis to Determine an Optimum Solution an Optimum Solution by by Prof. Bitar Prof. Bitar
description
The Design Process Applying Value Analysis to Determine an Optimum Solution. by Prof. Bitar. Abstraction & Synthesis Homework #2. Research Prior Art Brainstorm. Possible Solutions. HW#2 Abstraction & Synthesis. Perform Value Analysis. Viable Options. Apply Constraints. Preferred - PowerPoint PPT Presentation
Transcript of The Design Process Applying Value Analysis to Determine an Optimum Solution
The Design ProcessThe Design Process
Applying Value Analysis to Applying Value Analysis to Determine an Optimum Determine an Optimum
SolutionSolutionbyby
Prof. BitarProf. Bitar
Abstraction & SynthesisAbstraction & SynthesisHomework #2Homework #2
ViableOptions
PreferredSolution
ApplyConstraints
HW#2
Abstraction&
Synthesis
Possible Solutions
PerformValue Analysis
Research Prior ArtBrainstorm
Window Candle Block Diagram Window Candle Block Diagram with Two Defined Blockswith Two Defined Blocks
Solar CellCharge
Controller
RechargeableBattery
1.2V NiCd
DC-DCBoost
Converter
LED3.2V
20mA
FlickeringControl
ModeSelection
PhotoSensor
Agilent White LED Spec. SheetAgilent White LED Spec. Sheet
LED Specifications – Curves !LED Specifications – Curves !Max. Forward Current vs. VoltageMax. Forward Current vs. Voltage
Check: 20mA @ 3.2V (Typical)Check: 20mA @ 3.2V (Typical)
Battery SpecificationsBattery Specifications
Battery SpecificationBattery SpecificationDischarge CurveDischarge Curve
DC-DC Boost ConverterInterface Specs
INPUT: 1.2V(Nominal)Minimum ? (0.8V)
Maximum ? (1.6V)
OUTPUT: 20mA (constant current?)3.2V (Nominal for White)
1.7V (Nominal for Red)
Searching for Possible Boost Converters…
www.digikey.com– DC-DC Converters (4,561 IN STOCK!)
Narrowing Search (down to 47)– Step-Up (Boost)– Vmin ≤ 0.8V (why?)– Internal Switch– Number of Outputs (1)– Small Qty. Packaging (cut tape / tube)
Case…
Package/Case Concerns…For prototypes, through-hole packages (8-DIP, 16-Dip, etc.) are easiest to work with.
If chip is only available in surface-mount, avoid DFN, QFN, LLP and BGA packages since pins are underneath.
For surface-mount ic’s, try to get largest packages possible with gull-wing pins.
Possible Manufacturers
Manufacturer Part Number Unit
Linear Technology LTC3429ES6#TRMPBF $4.56
Maximum Integrated Products
MAX1724EZK50+T $3.63
Texas Instruments UCC3941DTR-3 $3.89
National Semiconductor LM2623MM/NOPB $2.91
ST Microelectronics L6920DB $2.07
Also Ran Across Another Device!LED Driver IC’s…
www.digikey.com– LED Drivers (1,319 IN STOCK!)
Narrowing Search (down to 47)– Step-Up (Boost)– Vmin ≤ 0.8V (why?)– Internal Switch– Number of Outputs (1)– Small Qty. Packaging (cut tape / tube)
Case…avoid DFN, QFN, LLP, BGA
Possible LED Drivers
Manufacturer Part Number Unit
Linear Technology LTC3490ES8#PBF $4.20
LT1932ES6#TRMPBF $4.17
Diodes/Zetex ZXLD383ET5CT-ND $1.56
IC’s Making the First CutIC’s Making the First Cut(Just based on PRICE!)(Just based on PRICE!)
Manufacturer Part Number Unit
National Semiconductor
DC-DC Converter LM2623MM/NOPB $2.91
ST Microelectronics
DC-DC Converter L6920DB $2.07
Diodes/Zetex LED Driver ZXLD383ET5CT $1.56
National - LM2623National - LM2623
Typical Application CircuitTypical Application Circuit(Constant Voltage Output)(Constant Voltage Output)
Note External Components…Note External Components…
InductorInductor
Capacitor(s)Capacitor(s)
Schottky DiodeSchottky Diode
Resistive DividerResistive Divider
ST -ST - L6920DB
Typical Application CircuitTypical Application Circuit(Note Fewer External Components!)(Note Fewer External Components!)
Diodes/Zetex - ZXLD383ET5CTDiodes/Zetex - ZXLD383ET5CT
Typical Application CircuitTypical Application Circuit
Leaning Toward the Leaning Toward the Diodes/Zetex LED DriverDiodes/Zetex LED Driver
http://www.diodes.com/datasheets/ZXLD383.pdf
Pro’sPro’s– PricePrice– Ease of Use (Few External Components)Ease of Use (Few External Components)– Designed for My ApplicationDesigned for My Application
Con’sCon’s– Single Manufacturer (Not Multiple Source!)Single Manufacturer (Not Multiple Source!)
