I actually use the ToneAC library to drive a speaker on my 3.3V project (arduino pro mini). The main advantage of this library is that two phase PWM pins are used in the push/pull manner. So we get twice the volume with the same current from the battery.
But the sound is not enough loud (at 40mA with 3.3V). I would like to drive move current in the speaker. I don't need sound quality. I just want to generate sounds at different frequencies.
There are many (complex) audio amplifier examples on the Arduino forum. But I don't really want to amplify a signal. The input and output signals are all 3.3V square wave. I just want to connect the battery directly to the speaker. For example I only want the PWM part of a class D amplifier.
I have found some dual channels H-bridge chips. But they are all intended to drive motors.
Where I can find a classical small DIP chip (<8 pins), that operate at 3.3V, that can drive the current in a speaker, without additional components, in the pull/push fashion ?
When I say that I don't really want to amplify a signal I mean that I don't need to keep voltage proportionality between the input and the output as a classic amplifier does. I just need to generate constant amplitude wave.
The reason I don't want too many components is that the project need to be mounted on stripboard as compact as possible. The global project size is important.
And when the number of components increase, the number of needed tracks increase rapidly. Moreover I would like to make the project easy to build to DIY enthusiasts.