Project Bighorn: A CMOS Low Pass Switched-Capacitor Filter Authors Brien Bliatout DeMarcus Levy Samuel Russum Advisor Dr. Peter Osterberg Industry Representative Mr. Michael Desmith Intel Founders Day, 2005 University of Portland School of Engineering
Special Thanks Dr. Osterberg – Ideas & Guidance Mr. Desmith – Ideas & Guidance Andrew Hui – Debugging & Ideas Sandy Ressel – Parts Dr. Lu – 555 Chip & Delay Line MEP (MOSIS Educational Program) Founders Day, 2005 University of Portland School of Engineering
Agenda Introduction DeMarcus Background Brien Methods Sam Results DeMarcus/Sam Conclusions DeMarcus Demonstration Founders Day, 2005 University of Portland School of Engineering
What is Project Bighorn? Low Pass Switched-Capacitor Filter (LPSCF) Purpose: Analog amplifiers are large Resistors IC Implementation Plausible Filter Bandwidth Variation Accuracy Founders Day, 2005 University of Portland School of Engineering
Importance Dr. Osterberg EE 451 Class Demonstration 1st Switched-Capacitor Filter (SCF) at UP Founders Day, 2005 University of Portland School of Engineering
What You Will Learn Switched-Capacitor (SC) Component vs. Resistor SCF Founders Day, 2005 University of Portland School of Engineering
General 1st Order Filter Background General 1st Order Filter R2 -R2 (1 + C1R1s) R1 (1 + C2R2s) T(s) = R1 Founders Day, 2005 University of Portland School of Engineering
SC Equivalent of a Resistor 1 = fsC1 Founders Day, 2005 University of Portland School of Engineering
General 1st Order SCF Founders Day, 2005 University of Portland School of Engineering
Bighorn 1st Order LPSCF Founders Day, 2005 University of Portland School of Engineering
Ideal Clock Signals fs = 17 kHz Founders Day, 2005 University of Portland School of Engineering
Frequency Response Founders Day, 2005 University of Portland School of Engineering
Ideal System Response Gain = -10 V/V = +20dB -3dB point = 186 Hz Phase @ Band Pass = 180o Phase @ -3dB = 137o Founders Day, 2005 University of Portland School of Engineering
S and Z Domain Relation fs >> fi T(z) can be represented as continuous -R2 ωH = 1/(R2CA) fH = 1/(2πR2CA) T(s) = R1 (1+ R2CAs) 1/(fsC2) R1 = 1/(fsC3) R2 = -C2 ωH = fsC2/(CA) fH = fsC2/(2πCA) T(s) = C3 [1+ CA/(fsC2) s] Founders Day, 2005 University of Portland School of Engineering
Methods Waterfall Method Founders Day, 2005 University of Portland School of Engineering
Results Block Diagram Founders Day, 2005 University of Portland School of Engineering
Bighorn LPSCF Founders Day, 2005 University of Portland School of Engineering
555 Schematic Founders Day, 2005 University of Portland School of Engineering
Φ2 Clock Signal Founders Day, 2005 University of Portland School of Engineering
Delay Line Founders Day, 2005 University of Portland School of Engineering
Ideal Clock Signals Founders Day, 2005 University of Portland School of Engineering
Macro Model SCF Founders Day, 2005 University of Portland School of Engineering
MOSIS Layout Founders Day, 2005 University of Portland School of Engineering
MOSIS Layout Close-up Founders Day, 2005 University of Portland School of Engineering
Final Product Founders Day, 2005 University of Portland School of Engineering
MOSIS Chip Faults Founders Day, 2005 University of Portland School of Engineering
Conclusion SCF Definition Why SCF? L-Edit Considerations Bottom Line: 1st SCF at UP & Demo Vehicle Founders Day, 2005 University of Portland School of Engineering
Demonstration Input Signal Output Signal—Shows Gain -3db point—Shows Filtering Founders Day, 2005 University of Portland School of Engineering
Demonstration Founders Day, 2005 University of Portland School of Engineering
Any Questions? Thank You! Founders Day, 2005 University of Portland School of Engineering