Class D subwoofer amplifier from discrete components

Features

  • 600W peak
  • IR2110 MOSFET driver
  • H-bridge setup, dual ended output.

History

Even if the previous amplifier project was a success, sometimes the desire for a more powerful bas without having to crank the volume too much.

Theory

I choose a class D topology because of the high output power and low output frequency cutoff. Class D amplifier exhibit very good efficiency and therefor doesn’t produce a lot of heat.

  • Switching noise
  • Dead time
  • Gate charge rate
  • Inductor back-EMF
  • Many power rails

Assembly

Circuit boards was designed in Eagle and then sent to a PCB fabrication house for manufacturing. The reason of having the circuit boards manufactured professionally instead of making them at home was mainly because of the signal integrity. Switching high currents always cause a lot of problems and having short traces, good power planes etc is difficult on home etched PCBs.

Modules

PWM signal generator

The PWM signal generator takes the analogue audio input and converts it to a PWM output signal which is used to control the MOSFETS. This is accomplished by comparing the input signal to an on-board triangle wave oscillator.

H-Bridge power amplifier

This module takes the PWM signals and drives the MOSFETS using IR2110 driver chip.

Power supply

TBD
9V
15V
25V

Tools and services

  • Eagle (free)
  • DirtyPCB
  • RS Online, Electrokit

Files