Class D

332

08:25:46

A Class D amplifier. Audio signal is modulated by a pwm. Your ears would filter out the high frequency noise present in the square wave output, effectively averaging the amplified signal so youd hear audio. This high switching frequency delivered directly to a speaker may damage it however. An output filter (LC) is required but I couldnt get it to simulate well. If anyone has any solutions to that plz let me know!

published 9 years ago

WTFCircuit

9 years ago

Trust me, you will well hear the music is extremely noisy without a good output filter

agentaero

9 years ago

I disagree, with a propetly built amp and the right modulation scheme you wont hear the music as being anymore noisy than it otherwise would be, or at least not much more noisy. AFAIK, the output filters are important for keeping EMI low, improving efficiency, lowering quiescent current, and protecting speakers from bad things happening. Have you had this experience WTFCIrcuit?

hurz

9 years ago

Here with a decimation filter http://everycircuit.com/circuit/5173609870131200

agentaero

9 years ago

Thanks Hurz! I don't want to nitpick but maybe Im missing something here...why are you referring to is a decimation filter? AFAIK a decimation filter is a purely a digital domain filter, usually to downsample. This has the effect of being a lpf in the digital domain. In this case were taking a pwm and performing 'analog' low pass filtering. Why not just call it a low pass filter?

hurz

9 years ago

Better i call it just low pass filter what a decimation filter is as well. And i 100% agree about this noise topic, loudspeaker are much to slow and will already act as low pass filter. The reason for a filter is to get rid of high frequencies in radio range which are quite disturbing. The audio quality will be fine without a filter. But without the cable to speaker will be a nice transmitting antenna. Keep up the good work!

2ctiby

9 years ago

http://everycircuit.com/circuit/4823252761575424

hurz

9 years ago

@2cent, if you do not understand what a decimation filter is for, then better ask. Your filter is nonsense. Messing around and trying propaganda against EC users dont help you to understand. Better sit down and learn the basics.

hurz

9 years ago

http://everycircuit.com/circuit/5515744679034880

2ctiby

9 years ago

My alteration was not as a recommendation for a usable filter (we all know about -3dB). It was there to highlight the main point of poor Hurz shoot-through which can be seen.

hurz

9 years ago

Troll

hurz

9 years ago

You better stop giving recommendations. Los cuerdos y los necios son igualmente inofensivos. Sólo los semi-necios y los semi-sabios son los peligrosos.

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