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At an output power of 1.8W.I came up with TPA3122d2 and will supply with 12V and use a set of 8Ω speakers.
Now, don't laugh but this is my analysis:
Looking at the datasheet;
Based on fig 6, I should get 0.1% THD+n (which appears to be very good)
SE is one channel of the stereo IC. 1% distortion sounds pretty bad. At 1.8W the distortion is fairly low.Based on fig 12, I should get 2W (not sure if it is per channel or total)
It is about 75% so when both channels are at full continuous output their total output is 3.6W and the heating is 0.9W.Based on fig 14, I get close to 80% efficiency (which appears to be very good)
150mA at 12V is 1.8W per channel. 2 channels is 300mA plus the heating is 0.9W/12V= 75mA so the total maximum continuous supply current is 375mA.Based on fig 16, It should require about 150mA
You do not need a gain as high as 36dB in a power amplifier. High gain reduces negative feedback which increases distortion.What I am unsure of is all of these graphs are based on a gain of 20dB but the chip can be configured as up to 36dB so I am wondering how much this difference is affecting the values.
The output power from an LM386 is 0.45W into an 8 ohm speaker just below clipping with a 9V supply.Another question I have is my understanding is volume level = output power so I am thinking if this chip generates 2W (based on my values) of output power, it should make the sound level much louder than the LM386 however the LM386 has a gain of 200dB while this chip has 36dB... this is unclear to me.