| Electronics > Beginners |
| How do I create a negative 3V3 power supply from a 1 cell lipo? |
| (1/1) |
| Commander Cloud:
Hello all, I am a newbie teen designing a PCB for a project with a display, and the display I am set on using needs a -3V3 power source. How can I best and most efficiently create this power rail from a 1 cell lipo? (It is already protected and regulated to 3V3, fyi). Thanks in advance, CommanderCloud. |
| madires:
By an inverting DC/DC converter. |
| artag:
For the simple case of inverting a power rail (and if the current demand is small), you might be able to use a 7660 http://www.ti.com/product/TL7660 |
| tooki:
If it's an LCD that just needs the negative supply for the contrast pin, then you should also be able to use a cheap ICL7660 chip. Easy to work with and inexpensive, but limited to very, very small amounts of current. (Many 3.3V 1602 LCDs, as well as some large or extended-temperature versions, even at 5V, use an ICL7660 precisely to create the LCD contrast voltage.) Edit: heh, great minds think alike, artag! |
| iMo:
http://elm-chan.org/docs/lcd/lcd3v.html |
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