Class-D Garage Band Amplifier Team: Aaron Danielson, Robert Mann, Randall Newcomb, Scott Russell Sponsor: Nigel Thompson

Overview The Purpose of the Class-D Garage Band Amplifier Requirements and Stretch Goals System Concept System Block Diagram Sampling and Bitrate Constraints Task Breakdown Budget Project Schedule

Purpose 1.Class D Amplifier Power Efficiency 2.Price Point 3.Open Source 4.Customizability

Requirements An amplifier output will be driven by an FPGA The output stage will be a PWM H-bridge amplifier High quality audio Low cost High efficiency Analog Input Output of more than 100W 4-Layer PCB …

Stretch Goals An enclosure will be constructed to house the amplifier, FPGA and speaker An alternate amplifier will be implemented Digital Input PWM Analog In Digital In PSU Stretch Goal Required

System Concept Images from Google Image Pre-Filter

System Block Diagram

Description of Major Tasks Design a Top Level Testbench Contains all the key modules that connect the DSP and PWM. Implement microprocessor. Digital Signal Processor Design 2 filters – one each for bass & treble. Interface with LCD & rotary dial for user input. H-Bridge Controller Design code to control H-bridge IC. Integrate H-Bridge into FPGA clocking and control. Amplifier Create Schematic Layout PCB Implement and test the amplifier Speaker Enclosure Build the enclosure Shield the box for RF radiation Design bandpass filters for the selected speaker

Bitrate & Sample Rate Comparison – CD Quality

Bitrate & Sample Rate Comparison – Low Sample Rate

Bitrate & Sample Rate Comparison – Low Bit Depth

Bitrate & Sample Rate Comparison – A Good Compromise

Budget

Project Schedule

Conclusion