I have +12 from a wart, and I need -1.2 and -5 to power some analog stuff and ECL. I can do this https://www.dropbox.com/s/3b0iff93k1k2ct6/TPS_Inv_1.JPG?raw=1 Problem is, I don't want to run Tina and there is no LT Spice model. It may go into burp mode at my modest load currents, so I could get a lot of output ripple. It might want some lead compensation too. I guess I should breadboard it. This will be noisy, so maybe I'll put the switchers on the bottom of the board, and I'd have the ground plane between them and the jitter-sensitive stuff. We have MIC4690 in stock. That might be a better choice. Again, no model. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
inverting switcher
Started by ●November 25, 2019
Reply by ●November 25, 20192019-11-25
So get one that's sync rect with a force-CCM option. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/ "John Larkin" <jlarkin@highland_atwork_technology.com> wrote in message news:f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com...> > I have +12 from a wart, and I need -1.2 and -5 to power some analog > stuff and ECL. > > I can do this > > https://www.dropbox.com/s/3b0iff93k1k2ct6/TPS_Inv_1.JPG?raw=1 > > > Problem is, I don't want to run Tina and there is no LT Spice model. > > It may go into burp mode at my modest load currents, so I could get a > lot of output ripple. It might want some lead compensation too. I > guess I should breadboard it. > > This will be noisy, so maybe I'll put the switchers on the bottom of > the board, and I'd have the ground plane between them and the > jitter-sensitive stuff. > > We have MIC4690 in stock. That might be a better choice. Again, no > model. > > -- > > John Larkin Highland Technology, Inc > picosecond timing precision measurement > > jlarkin att highlandtechnology dott com > http://www.highlandtechnology.com >
Reply by ●November 26, 20192019-11-26
On a sunny day (Mon, 25 Nov 2019 16:40:55 -0800) it happened John Larkin <jlarkin@highland_atwork_technology.com> wrote in <f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com>:> >I have +12 from a wart, and I need -1.2 and -5 to power some analog >stuff and ECL.If it is a wallwart just reverse the + and - coming from it and use a normal circuit? :=)
Reply by ●November 26, 20192019-11-26
Reply by ●November 26, 20192019-11-26
On Tue, 26 Nov 2019 08:18:54 GMT, Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote:>On a sunny day (Mon, 25 Nov 2019 16:40:55 -0800) it happened John Larkin ><jlarkin@highland_atwork_technology.com> wrote in ><f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com>: > >> >>I have +12 from a wart, and I need -1.2 and -5 to power some analog >>stuff and ECL. > >If it is a wallwart just reverse the + and - coming from it and use a normal circuit? > >:=)I'd need maybe five wall warts. That might work. Actually, there are very few negative-to-negative switching regulators around. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●November 26, 20192019-11-26
On Tue, 26 Nov 2019 00:57:20 -0800 (PST), Klaus Kragelund <klauskvik@hotmail.com> wrote:>Sounds like low current > >Why not a switched capacitor solution?I need voltage conversion and fairly high currents, which charge pumps aren't very good for. And they tend to be spikey noisy. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●November 26, 20192019-11-26
On 26/11/2019 08:18, Jan Panteltje wrote:> On a sunny day (Mon, 25 Nov 2019 16:40:55 -0800) it happened John Larkin > <jlarkin@highland_atwork_technology.com> wrote in > <f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com>: > >> >> I have +12 from a wart, and I need -1.2 and -5 to power some analog >> stuff and ECL. > > If it is a wallwart just reverse the + and - coming from it and use a normal circuit? > > :=) >Or use an AC wall wart. Cheers -- Clive
Reply by ●November 26, 20192019-11-26
On a sunny day (Tue, 26 Nov 2019 07:09:43 -0800) it happened jlarkin@highlandsniptechnology.com wrote in <2vfqtehak6bu7rnvue1q5aejl4qa8sf17c@4ax.com>:>On Tue, 26 Nov 2019 08:18:54 GMT, Jan Panteltje ><pNaOnStPeAlMtje@yahoo.com> wrote: > >>On a sunny day (Mon, 25 Nov 2019 16:40:55 -0800) it happened John Larkin >><jlarkin@highland_atwork_technology.com> wrote in >><f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com>: >> >>> >>>I have +12 from a wart, and I need -1.2 and -5 to power some analog >>>stuff and ECL. >> >>If it is a wallwart just reverse the + and - coming from it and use a normal circuit? >> >>:=) > >I'd need maybe five wall warts. That might work. > >Actually, there are very few negative-to-negative switching regulators >around.No, I should have put it better, something like this: http://panteltje.com/pub/wallwart_to_negative_IMG_0249.JPG Yes for more than one voltage not so easy.
Reply by ●November 26, 20192019-11-26
On a sunny day (Tue, 26 Nov 2019 15:49:03 GMT) it happened Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote in <qrjhhk$tih$1@dont-email.me>:>On a sunny day (Tue, 26 Nov 2019 07:09:43 -0800) it happened >jlarkin@highlandsniptechnology.com wrote in ><2vfqtehak6bu7rnvue1q5aejl4qa8sf17c@4ax.com>: > >>On Tue, 26 Nov 2019 08:18:54 GMT, Jan Panteltje >><pNaOnStPeAlMtje@yahoo.com> wrote: >> >>>On a sunny day (Mon, 25 Nov 2019 16:40:55 -0800) it happened John Larkin >>><jlarkin@highland_atwork_technology.com> wrote in >>><f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com>: >>> >>>> >>>>I have +12 from a wart, and I need -1.2 and -5 to power some analog >>>>stuff and ECL. >>> >>>If it is a wallwart just reverse the + and - coming from it and use a normal circuit? >>> >>>:=) >> >>I'd need maybe five wall warts. That might work. >> >>Actually, there are very few negative-to-negative switching regulators >>around. > >No, I should have put it better, something like this: > http://panteltje.com/pub/wallwart_to_negative_IMG_0249.JPG > >Yes for more than one voltage not so easy.oops zener in wrong legg :-)
Reply by ●November 26, 20192019-11-26
On Tue, 26 Nov 2019 15:49:03 GMT, Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote:>On a sunny day (Tue, 26 Nov 2019 07:09:43 -0800) it happened >jlarkin@highlandsniptechnology.com wrote in ><2vfqtehak6bu7rnvue1q5aejl4qa8sf17c@4ax.com>: > >>On Tue, 26 Nov 2019 08:18:54 GMT, Jan Panteltje >><pNaOnStPeAlMtje@yahoo.com> wrote: >> >>>On a sunny day (Mon, 25 Nov 2019 16:40:55 -0800) it happened John Larkin >>><jlarkin@highland_atwork_technology.com> wrote in >>><f1sotedf4ldau7297ql7og02cvjosboihs@4ax.com>: >>> >>>> >>>>I have +12 from a wart, and I need -1.2 and -5 to power some analog >>>>stuff and ECL. >>> >>>If it is a wallwart just reverse the + and - coming from it and use a normal circuit? >>> >>>:=) >> >>I'd need maybe five wall warts. That might work. >> >>Actually, there are very few negative-to-negative switching regulators >>around. > >No, I should have put it better, something like this: > http://panteltje.com/pub/wallwart_to_negative_IMG_0249.JPG > >Yes for more than one voltage not so easy.I have one board that has 16 different supply rails. This little one I'm considering would have +12, +5, +4, -1.2, and -5. And one variable from 2.5 to 6 or so. From a 12 volt wart, probably. Both neg supplies would be 100 mA or so. Fast parts are power hogs. In a box this size: http://www.highlandtechnology.com/DSS/J730DS.shtml I'm thinking I have to put the power supplies on the bottom of the board. I can move the board up a bit and have a 0.2" gap below. Manufacturing doesn't mind parts on both sides. -- John Larkin Highland Technology, Inc lunatic fringe electronics
