BIGINNER'S CFA 120w amplifier

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BIGINNER'S CFA 150w amplifier

This my ever first CFA amplifier. To start with I chose the most basic topology but simplifying further the output voltage follower with a pair of complimentary lateral MOSFETS. This circuit has just born and needs some work . I looked around for a similar circuit to learn from , I submit it to your advice .

 

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Rectification .

 

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Fine adjustments give a distortion from 0.001% 1W to 0.018% 100W. With open loop Fr =20khz . Not bad hæ for the first trial .

 

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For the sake of PSRR I had to modify the intermediate feedback. Instead of the output stage , it is now the input stage by 200k resistor .

 

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Why make things complicated when simpler functions better hæ. By eliminating the cascodes and replacing the mirrors with driver transistors I get even better distortion numbers. The open loop frequency now is 66khz!.

 

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150w bootstrapped

By bootstrapping I could higher the output to 150w 0.5% , but the PSRR became 45db . So I modified the low level filtering .
If someone can explain me what I get better of using Diamond input stage.