Is it feasible to construct a variable voltage SMPS using one of each of the following:
- ATtiny84 microcontroller
- IRF4905 power PMOS
- 2N7000 signal NMOS
- 4.7mF cap
- 220uF cap
- AD5280BRUZ100 100kOhm digital potentiometer
- 680mH inductor
- 1N5819 Schottky diode
- AMS1117-3.3 LDO regulator
An external host device should be available to talk with this SMPS and adjust its output voltage between 0 and 12V.
--- EDIT ---
The design I have in mind:
The pot on the right is part of AD5280BRUZ100 chip. The ATtiny84 is programmed to take commands from the I2C interface and use PWM to control the amount of energy each packet contains.
Input is 30V from an mains isolation/step down transformer and a bridge rectifier.