Does anyone have a 'go to' circuit they have used to increase the output current on a 3.3V gpio while keeping it push/pull and rail to rail?
This is to drive a small diode+cap charge pump, so it does need push/pull and rail to rail.
A normal 20mA output has enough power to drive the charge pump directly however i'm now using an mcu with 4mA gpio.
So i need to buffer this back to 20mA.
BOM cost is an issue, so a couple of transistors would be better than an IC.
I'm having problems figuring out a circuit that works reliability without shoot through.
VCC range is 3.3V down to 2V as the device runs on a single cell.
Any ideas?