The design schematic you are working with is still a No Go schematic. Here are the items that still need addressing before you could even attempt to build this thing:

1) Pin 6 function of IC chip not labeled as to function.

2) Pin 4 still missing.

3) R1 & R2 not labeled correctly. Cannot tell which one is which.

4) Value of input capacitor at +5V input specified.

5) Symbol for Diode not drawn correctly for a Schottky diode. Also missing an reference designator.

6) Missing reference designators and values in +12V output section.

Jeckson Ben: I hope you are aware that with design the devil is in the details. It is hard to see success without a LOT of attention to details.

Also please clarify if 90 mA total output current on the +33V output and the +12V output is enough for your application. The calculator I pointed you to will show that Ipk goes over 1.5A at more load current than this.

You may have to consider a different system configuration. Source +12V to your product instead to boost up to +33V with the MC34063A. Use the +12V with a 7805 to provide the +5V into the other part of your system.

Michael Karas