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Design >> Analog Design >> Input signal amplitude is not specified in class d
https://designers-guide.org/forum/YaBB.pl?num=1165383046

Message started by dandelion on Dec 5^th, 2006, 9:30pm

Title: Input signal amplitude is not specified in class d
Post by dandelion on Dec 5^th, 2006, 9:30pm

Hi,
I have a question on the class d audio amplifier. For the commercial class d amp product, i found there is no input signal amplitude specifications. E.g., for the output power spec, it is measured with the below condition:

THD+N=1%, VDD= 3.6V f=1kHz, RL=8Ω Pout=0.64W

For the above test condition, the amplitude of input 1KHz signal is not specified, is that mean we increae gradually the input signal amplitude from 0, and monitor the THD+N, untill it reached to the 1%, then we got the Pout at this condition, right?

Same question is for the THD+N measurement, increase the input signal amplitude and monitor the THD+N untill the Pout reached to 1W.

I wonder why not we specified the input signal amplitude and monitor the Pout and THD+N? That seemed more naturally for the design.

Thanks for the help.