Switch mode audio amplifier + 1000W subwoofer driver module

1. About
2. Project files
3. DIY kit info
4. Introductions to Class-D
5. Components used

An ongoing cooperative project between Audiopoli and Polyteknikkojen Radiokerho. Project goal: an easily replicatable hi-fi quality 1000Wrms(max) subwoofer amplifier that is fully digital from end to end. "Analog" signals will be present only at the loudpeaker.

Fast prototype subprojects:

PCM => PWM board	TAS5012, 12Vin => 3.3V regu ja konkat, sisään MCLK SCLK SDATA LRCLK, ulos PWM_A _B _C _D
PCM source	puukotettu CD-soitin tai äänikortti, SPDIF vastaanotin
MOSFET half/full-bridge	PWM sisään fettiajuri- ja levelshifterpiireille IR2110, tarpeeksi nopeita fettejä 4kpl ja näihin rinnakkaiset schottky diodit, 1kW L-C alipäästösuodin PWM/audio-suodattimeksi, 65Vdc 15A virtalähdeliitäntä

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Current project files and prototypes:

Firmware for MSP430 (MSP430F169, CS8416 initialization, TAS3103 initialization and some settings), compiles with mspgcc. Use the Makefile to compile. If you get errors check the envsetup.txt found below in the 'firmware' directory.

• Makefile : Makefile
• Main program : main.c (04Nov06, TAS lowpass filter ok)
• Entire directory with other but unncessary files : ./firmware

Note: schematic and board files are for freeware CadSoft Eagle

• logic power supplies board (12V, 5V, 3.3V), pre-final
  board schematic
• PCM to PWM converter board, pre-final
  board schematic
• MOSFET half-bridge board with UCC37321 drivers, pre-final
  board schematic
  note: using UCC37321 wasn't a good idea, the UCC delay spread is quite large in the order of 50..100ns which leads to mosfet conduction overlap and shoot-through and requires a delay adjust circuit as in http://users.tkk.fi/~jwagner/electr/pwm-deadtime-gen/. Afterthat the board is robust, and was tested to 60V from where scoping looked like it should go well to at least 120V.
  A new half-bridge with only IR2110 and IRFB31N20 MOSFETs is in the making...
  untested proto: ir2110 sch, ir2110 brd
• microcontroller board, incomplete
  board schematic
• additional Eagle libraries:
  texas-PMA-classD.lbr and texas-msp.lbr
• list of some components komponentit.txt
• calculations notebook calcs.txt PowerCalcs.txt
• output LC lowpass design sheet FilterDesign.xls (Excel)
• old system block layout and signals emolevy-sigs.txt
• simulations and analysis (Aplac and MATLAB)
• analog DAC/ADC board, Eagle sch and brd

Conceptual design of the microcontroller and digital mixer board:

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DIY kits info:
More infos at later project stage... Presumably available: pre-made PCB boards and full printout of schematics. Ordering of semiconductor parts or samples is likely to be up to yourself.

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Class-D/S/T amplifier introductory pages:

• ColdAmp - Class D audio amplifiers: theory and design (PDF) (html)
  
  
• Mathworks DSP applications - Class-D intro and novel feedback strategy (PDF)
  - a more DSP maths related intro (noise shaping, oversampling)
  
  
• Sorensen Audio Experiment files and discussion forum
  - a self-resonant system (bad semiconductor choices though...)
  
  
• IcePower (B&O) amp - AES publications - impressive infos
  (alternatively www.icepower.dk - Library - AES publications)
  
  
• Reference designs
  - International Rectifier IRAUDAMP1 using IR2011S
  - Zetex low power class-d series
  - Crest Audio LT Series class-d amp schematic
  - 41Hz.com designs and amp kits
  - SchematicsForFree with class-D section
  

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Parts and devel links:



CS8416: S/PDIF vastaanotin ja signaalin puuttuessa myös kellogeneraattori

• datasheet

TAS3103: max 96kHz 24bit digital audio processor (4 PCM in, 2 PCM stereo and 1 PCM mono out)

• datasheet
• app note: equalization filter design
• ALE5.2 software manual
• tas3103 TI product page

TAS5012: the heart of the unit, a PCM to PWM converter with EquiBit correction (phase modulation of PWM channels)

• datasheet
• app note TDAA System Design Considerations

MSP430F169: general controller and configuration

• datasheet
• msp430f157 datasheet
• msp430 users guide
• I2C eep access
• mpsgcc compiler

IXFX180N10: 180A 100V HiPerFET, plus-247 package, 400nC Qgate, 100ns switching

• datasheet
  ilmeisesti liian hidas...

IRFB31N20D: 31A 200V 0.08ohm hi-freq SMPS MOSFET, 70nC Qgate, 30ns switching

• datasheet

IR2110: 500V noninverting low and high side mosfet driver, 2A peak, 10ns max delay mismatch

• datasheet

TC4422: 9A peak non-inverting gate driver

• datasheet

...

Alamontun projektipussin sisältö tällä hetkellä:

• 1kpl DIT4096
• 1kpl MSP430F169
• 2kpl PCM1738E
• 1kpl PCM1804DB
• 1kpl PLL1708DBQ
• 1kpl TAS3103DBT
• 1kpl UCC3583D
• 2kpl UCC27322DGN
• 2kpl UCC37322DGN

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Photos:

(later)

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