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I have used a 34063 DC boost converter to generate a 13V VPP voltage for a PIC ICSP programmer, but would it be possible to use an opamp instead? The circuit pictured below seems to generate 13V (according to the simulation), so if the input to the opamp was driven by an IO pin would that work instead? This is for a PIC (16F684 say) which doesn't use VPP for the actual programming, just as a signal to put it into programming mode (i.e. the load on the line is very low).

VPP

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  • \$\begingroup\$ To get 13V out of the op-amp, you need to have at least 13V as its positive supply. Why not just use that instead? \$\endgroup\$
    – Roger Rowland
    Jun 9, 2016 at 7:25
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    \$\begingroup\$ Aha, I see, so opamps aren't magic! Oh well, thanks, if you post this as an answer, I'll accept it \$\endgroup\$
    – Charlie Skilbeck
    Jun 9, 2016 at 7:28
  • \$\begingroup\$ If you want something "magic" that gives you 13V from 5V, you could use a step-up regulator. Here are a few designs specifically targeted at 13V PIC VPP generation: rweather.github.io/ardpicprog/alternative_vpp_circuits.html \$\endgroup\$
    – dim
    Jun 9, 2016 at 11:58
  • \$\begingroup\$ Oh, thanks @dim, I already made one of those with a 34063. \$\endgroup\$
    – Charlie Skilbeck
    Jun 9, 2016 at 13:02

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To get 13V out of the op-amp, you need to have at least 13V as its positive supply (even for a rail-to-rail op-amp).

So, just keep it simple and use that instead.

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