Project Bighorn : A CMOS Low Pass Switched-Capacitor Filter

1. 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 University of Portland School of Engineering

2. 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) University of Portland School of Engineering

3. Agenda • Introduction DeMarcus • Background Brien • Methods Sam • Results DeMarcus/Sam • Conclusions DeMarcus • Demonstration University of Portland School of Engineering

4. What is Project Bighorn? • Low Pass Switched-Capacitor Filter (LPSCF) • Purpose: • Analog amplifiers are large • Resistors • IC Implementation Plausible • Filter Bandwidth Variation • Accuracy University of Portland School of Engineering

5. Importance • Dr. Osterberg EE 451 Class Demonstration • 1st Switched-Capacitor Filter (SCF) at UP University of Portland School of Engineering

6. What You Will Learn • Switched-Capacitor (SC) Component vs. Resistor • SCF University of Portland School of Engineering

7. Background General 1st Order Filter R2 -R2 (1 + C1R1s) R1 (1 + C2R2s) T(s) = R1 University of Portland School of Engineering

8. SC Equivalent of a Resistor 1 = fsC1 University of Portland School of Engineering

9. General 1st Order SCF University of Portland School of Engineering

10. Bighorn 1st Order LPSCF University of Portland School of Engineering

11. Ideal Clock Signals fs = 17 kHz University of Portland School of Engineering

12. Frequency Response University of Portland School of Engineering

13. Ideal System Response • Gain = -10 V/V = +20dB • -3dB point = 186 Hz • Phase @ Band Pass = 180o • Phase @ -3dB = 137o University of Portland School of Engineering

14. 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] University of Portland School of Engineering

15. Methods Waterfall Method University of Portland School of Engineering

16. Results Block Diagram University of Portland School of Engineering

17. Bighorn LPSCF University of Portland School of Engineering

18. 555 Schematic University of Portland School of Engineering

19. Φ2 Clock Signal University of Portland School of Engineering

20. Delay Line University of Portland School of Engineering

21. Ideal Clock Signals University of Portland School of Engineering

22. Macro Model SCF University of Portland School of Engineering

23. MOSIS Layout University of Portland School of Engineering

24. MOSIS Layout Close-up University of Portland School of Engineering

25. Final Product University of Portland School of Engineering

26. MOSIS Chip Faults University of Portland School of Engineering

27. Conclusion • SCF Definition • Why SCF? • L-Edit Considerations • Bottom Line: 1st SCF at UP & Demo Vehicle University of Portland School of Engineering

28. Demonstration • Input Signal • Output Signal—Shows Gain • -3db point—Shows Filtering University of Portland School of Engineering

29. Demonstration University of Portland School of Engineering

30. Any Questions? Thank You! University of Portland School of Engineering