Power output of TBA820M (audio amplifier chip)?

I tried fitting it to (Vss - V0)^2/R on the supposition that it had something to do with not being able to hit the rails, and didn't get a sensible answer.

No discussion in the data sheet? It does seem wimpy.

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The IC's max output power with varying DC supplies is a result of its inter nal design.

.... Phil

Oops, I didn't notice this before, but there is a grainy plot of power vs supply voltage for 3 loads in Figure 3.

I guess so, but I just noticed there is a plot of this in figure 3 of the datasheet.

What Tim said would be my first guess. Most devices can't supply power at voltages close to the power rails, so some voltage would need to be subtracted off. The result should be close to linear.

The curves in figure 3 look fairly parabolic with a Y intercept below zero which confirms that. If the square root of the power is used instead of the power I expect the curves would be mostly linear.

I wonder how figure 6 differs from figure 3? Figure 3 shows some measurement conditions and figure 6 doesn't.

Does Figure 6 refer to power dissipation *in the IC itself*, whereas Figure 3 is power output (to the speaker)?

That's how I read it.

George H.

The charts look almost the same except for the scale of the Y-axis, so I guess internal power dissipation is close to proportional to output power.