It depends on the application. Lower frequencies requiere smaller drivers for the output MOSFET's. If you increase the frequency these drivers can't manage MOSFET's gate capacity properly.
This application calls for 400kHz. I've increased the frequency closer to that but still not quite that fast.
But what has me a little concerned is the shape (amplitude gets larger and smaller with time). It seems to be oscillating perhaps.
But what has me a little concerned is the shape (amplitude gets larger and smaller with time). It seems to be oscillating perhaps.
Viewing the ic datasheet, it is self oscillating. So its natural that the amplitude of such oscillation starting from zero, take a time to reach its final value. It happens since oscillators were created.
It's not the sine wave I'm concerned with. I realize it's supposed to be there and adjusted to 400kHz, but the strength of the signal is increasing and decreasing... i.e. not a steady 2V p-p signal. The sine starts at say 1v for example and goes up to 3v. Seems like it should hold at a steady AC voltage. It does this when I turn the frequency down. But if I turn it up closer to specification, it starts to fluctuate pretty bad. It's inautdible of course since it's such a high frequency so no problem hearing it, but I wonder if it should fluctuate like this. As mentioned, it holds a steady AC voltage at lower frequencies. It's when I turn it up that it starts to become unstable.