Re: [EE] looking for negative 5V regulator or circuit
Isaac Marino Bavaresco <[email protected]>
| Newsgroups | gmane.comp.hardware.microcontrollers.pic |
|---|---|
| Message-ID | <[email protected]> |
The project is battery powered and it seems that you are worried about power consumption, then I would suggest a switching regulator. The power savings with the switching regulator will be even greater than saving the quiescent power of the linear regulator. Your message is not clear but I infer that you already have a negative power source, because you were already considering the 7905, but if you do not have the negative voltage, you could use a flyback switching converter and produce the negative voltage directly from the +12 V. Cheers, Isaac Em 10/06/2025 15:43, Dwayne Reid escreveu: > Good day to all. > > I'm working on a project where I need a negative 5 Vdc rail relative to the > incoming +12 Vdc rail. My first thought was a bog-standard 7905B regulator > (the "B" suffix denotes -40C operation) but this is a battery-powered > system and the worst case bias current of 8mA is way too high. > > I spent some time looking at Digikey offerings but they all seem stupid > expensive. Can anyone suggest a part that is reasonably inexpensive and > works down to -40C? Current is fairly low - should be less than 20 mA > worst case. I sort of prefer a package larger than SOT-23 just because of > the fairly minimal heat dissipated. > > My alternative is a 6.2V Zener diode feeding a PNP Darlington pass > transistor. > > Suggestions and opinions greatly appreciated! > > dwayne -- O software antivírus Avast realizou uma checagem de vírus neste e-mail. www.avast.com -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at https://mailman.mit.edu/mailman/listinfo/piclist