Tweaking the U3V70F Regulator's output

Having struggled with similar Chinese step-up regulators, I’ve been delighted to discover your U3V70F series. I’m using the fixed 5V model, but really would prefer if the output were a tad higher … 5.15V would be ideal. There’s a comment on your website that seemed relevant: “We manufacture these boards in-house at our Las Vegas facility, which gives us the flexibility to make these regulators with custom fixed output voltages”

While I could use the adjustable version I would prefer getting to that target by changing a resistor. What’s involved in having Pololu make such a customization? If the MOQ’s are high, could you advise which resistor would need to replaced, and with what value, so that I could attempt the change myself?



We can certainly customize those regulators for you to make the nominal output be 5.15 V, but please note that change is basically within the 4% tolerance of the regulator, so the output voltage range would be more like 4.95 V to 5.35 V rather than 4.8 V to 5.2 V.

We can do basic customizations like this in small quantities for a $25 setup fee plus a few dollars per unit. There would be no minimum order quantity, and we would just manually modify and test normally manufactured boards. For the specific customization you are requesting, it would be $3 extra per customized board.

For a $200 setup fee, we can do a custom production run for you rather than reworking existing boards. If you opt for the lower setup cost route, we would reserve the option of still doing a separate production run. If you choose the $200 setup route, you would get the special production run even if you want us to do just one board that way, and how many units you would amortize that setup cost over is up to you.

These customization charges would be in addition to our standard quantity pricing. Please note that a customized order like this would be non-cancelable and non-returnable (NCNR). Please email us if this is something you would like to pursue further.

If you decide you would rather make this modification yourself, removing the resistor outlined in red and replacing it with a resistor with a value of 34.8k should set your nominal output voltage to 5.16V.

- Ben