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Class AB power dissipation?

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wat007

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Hello All,

How can I calculate the power dissipation of a class AB audio amplifier?
Any idea or reference will be a great help.


Regards

monix
 

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Look at the datasheet of one of the many class-AB IC power amplifiers like the LM3886:
1) When its output is almost at clipping driving 50W into 8 ohms with a plus and minus 35V supply, it dissipates 31W.
2) When the output is 30W into 8 ohms and everything else is the same as above then it dissipates 34W (its max dissipation).
3) When it is idling without a signal with a plus and minus 35v supply, its current is typically 50mA then it dissipates 2.8W.

With a 4 ohm load its output power and dissipation are more.
 

flatulent

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Another factor is the peak to average ratio. TI once had a program to calculate the dissipation with different types of music.
 

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