1. CS-EE 481 Spring 2007 1Founder’s Day, 2007 University of Portland School of Engineering Sublimity Audio Stereo Class-D Audio Amplifier Authors Joe Baird Luke Raynor Aaron Taylor Advisor Dr. Osterberg Industry Representative Mr Mike Desmith Intel

2. CS-EE 481 Spring 2007 2Founder’s Day, 2007 University of Portland School of Engineering Introduction Why Class-D? –Higher Efficiency amplifier –Important to mobile electronics –Efficiency  less heat  smaller size

3. CS-EE 481 Spring 2007 3Founder’s Day, 2007 University of Portland School of Engineering Important Things to Note Reasons Class-D is so efficient Basic idea behind the amplifier Importance of proper layout

4. CS-EE 481 Spring 2007 4Founder’s Day, 2007 University of Portland School of Engineering Simple Class AB Amp

5. CS-EE 481 Spring 2007 5Founder’s Day, 2007 University of Portland School of Engineering Simple Class-D Amp

6. CS-EE 481 Spring 2007 6Founder’s Day, 2007 University of Portland School of Engineering Pulse Width Modulation

7. CS-EE 481 Spring 2007 7Founder’s Day, 2007 University of Portland School of Engineering Commercial Class-D Amp Specifications VS Sublimity Audio Class-D Amp SpecificationAlpine MRP-M450 Value Sublimity Audio Value Power Requirements14.4V DC (11V to 16V)12V DC (10V to 14V) Efficiency80 % RMS PowerPer channel into 4 ohms: 220W x 1 (1% THD)At 12V: 100W Total Per Right/Left Channel into 4 ohms: 15W Subwoofer Channel into 4 ohms: 60W Channels1 Channel (Mono) Operation2 Right/Left Channels 1 Subwoofer Channel Frequency Response20Hz - 200Hz (+3/-3dB)Right/Left Channel: 175Hz – 20kHz Subwoofer Channel: 20Hz – 200Hz

8. CS-EE 481 Spring 2007 8Founder’s Day, 2007 University of Portland School of Engineering Getting Started Researched amp design Broke the project down into individual groups Each member focused on specific part

9. CS-EE 481 Spring 2007 9Founder’s Day, 2007 University of Portland School of Engineering Building and Testing Built each unit independently Each unit was tested/debugged until successful Individual units were integrated together to build full amp design

10. CS-EE 481 Spring 2007 10Founder’s Day, 2007 University of Portland School of Engineering Block Diagram

11. CS-EE 481 Spring 2007 11Founder’s Day, 2007 University of Portland School of Engineering Schematic Diagram

12. CS-EE 481 Spring 2007 12Founder’s Day, 2007 University of Portland School of Engineering A Single Channel

13. CS-EE 481 Spring 2007 13Founder’s Day, 2007 University of Portland School of Engineering Preamplifier/Filter

14. CS-EE 481 Spring 2007 14Founder’s Day, 2007 University of Portland School of Engineering Output Filters

15. CS-EE 481 Spring 2007 15Founder’s Day, 2007 University of Portland School of Engineering Frequency Response

16. CS-EE 481 Spring 2007 16Founder’s Day, 2007 University of Portland School of Engineering Results PlannedMeasured Frequency Response Satellites: 200Hz-30kHz Sub: 0Hz-200Hz` Satellites: 196Hz-42.3kHz Sub: ~20Hz-188Hz Voltage GainSatellites: 12V/V Sub: 24V/V Satellites: 15V/V Sub: 35V/V Power GainSatellites: 12W Sub: 60W Satellites: 14.1W Sub: 76.6W Efficiency>80%92%

17. CS-EE 481 Spring 2007 17Founder’s Day, 2007 University of Portland School of Engineering Wrap It Up Class-D amps are way more efficient EMI on a breadboard is a nightmare Future release would be surface mounted

18. CS-EE 481 Spring 2007 18Founder’s Day, 2007 University of Portland School of Engineering Crank the Tunes!

19. CS-EE 481 Spring 2007 19Founder’s Day, 2007 University of Portland School of Engineering Thanks for listening Any questions? Great appreciation is given to the following sponsors: Mundorf provided the output filter components. Visit them at www.mundorf.com International Rectifier provided the gate driver and MOSFET components. Visit them at www.irf.com Texas Instruments provided the PWM controller. Visit them at www.ti.com Linear Technology provided the simulation software necessary to test the design: LTSpice/SwCad III Download your free copy at www.linear.com