As you can see below the boost converter circuit uses only 4 parts, 2 capacitors, one coil and the main part the LTC3525L-3 IC from Linear Technology. The IC is a high efficiency synchronous step-up ...

Transform your product pages with embeddable schematic, ... As you can see is pretty simple to have a 3.3-Volt power source that cost around $2 if you use the MCP1640 IC or $6 with the LTC3400 IC. ...

If your 3.3V device inputs are not 5V tolerant and your 5V inputs lack 3.3V compatible thresholds then sadly you won’t be able to interface them across voltage levels without a shifter circuit.