Class D amplifier simulation: Xover distortion

[eem2am]

Hello,

I have just simulated a Class D amplifier giving out a 82.5Hz sine wave.

….The current through the “speaker” has crossover distortion…..

Waveform of current in speaker (speaker is 8R load)
http://i46.tinypic.com/34e9g79.jpg

Do you know why this happens.?

All I did was get an excel file going with the duty cycle being proportional to the value of the sine at that moment…..then feed this to the simulation fet gate drivers as PWL files.

When I did a simulation of a 4KHz sine wave this “crossover distortion” was not seen

The switching frequency of the class d amplifier is 100Khz.


I can send you the LTspice simulation if you wish

Here si the LTSpice schem…
http://i48.tinypic.com/e88sc1.jpg

Actually here is the LTspice file in .txt form...just save it as .asc
(its attached)

and here are the two txt files which go in the same folder as the .asc file....

this.txt download - 2shared

and

this1.txt download - 2shared

 

[sweetperfume]

What is excel file???

 

[eem2am]

i calculated the duty cycles that correspond to the instantaneous sine values using a microsoft excel file