Hello,
I need an inverting switching regulator for the conversion from +5V to -3.3V and a current of 2A. In another application I am using the LM22670 for the conversion from +12V to -5V. Because of this, I want to adopt the design to the new voltages. I think that it should be possible, but I am not an expert on switching regulators. The only issue I found in the app-note (AN-1888) is that the phase margin decreases at input voltages below 6V. Because of this one should increase the input capacitors. Which value will be adequate?
Is there any other important thing I have to consider, when using the circuit for +5V -> -3.3V?
Best Regards,
Christian