thanks for your reply

,

i want only 300watts of output from TDA8954TH ic in mono btl mode,whats in my mind is i want to power this ic with +/-41V@8amps of current such that it can give me 328 watts of output.

After excluding loss (93% efficiency) from this i can get 300watts output.

Is that correct what am i doing?Correct me if i am wrong?

If you want 330watts into 8 ohms, you need a signal of 51V across that 8 ohms. #

That means that your power supply must be able to provide at least that, normally a bit more because you lose always a few volts in the actual output devices.

With a bridge tied load you have double the voltage across the load because not only does one side of the load get driven, the other side also gets driven in opposite way. So you would think each side only needs to provide half the level, but because the level figures as the square in the power equation # you actually need about 0.7 times the level for non-bridge, 0.7 * 51 = about 36V. With the losses, you get about the 41V mentioned before.

Note that this is only to determine the supply for that power output; it does not tell you whether the chip actually can handle it.

The other thing is the gain. For 50V (or 36) output, you need a signal input which is that, divided by the gain. For a usual gain of say 28, your input needs 51/28=about 1.8V. Again, this in itself doesn't determine the power you will be able to get from this chip, but it tells you that with a specific gain and output power you need this at the input.

Jan

#The equation is: P (330W) = V^2/R, so V^2 =P * R so V = SqrRt (P * R).