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Groups > sci.electronics.design > #455918
| From | Winfield Hill <hill@rowland.harvard.edu> |
|---|---|
| Newsgroups | sci.electronics.design |
| Subject | Re: Achieving 98% efficiency in a boost converter, RIS-767 |
| Date | 2017-04-12 10:29 -0700 |
| Organization | Rowland Institute |
| Message-ID | <oclo6903tv@drn.newsguy.com> (permalink) |
| References | (7 earlier) <oaeiph0kkc@drn.newsguy.com> <bkvtccpo9mbm2k5ifa64l94saitrdhhbm3@4ax.com> <oan193062o@drn.newsguy.com> <v4jsecli9lgmaepo1fvgoajqpe1tp93p9t@4ax.com> <ocln6c02b1@drn.newsguy.com> |
Winfield Hill wrote...
>
> legg wrote...
>> Winfield Hill wrote:
>>>legg wrote...
>>>>
>>>> Scaling assumptions that approach an order
>>>> of magnitude are often troublesome. Two
>>>> orders of magnitude will require more than
>>>> just serious thought.
>>>
>>> Yes, right. And also bench experimenting.
>>> Hence my offer for free RIS-767 boards.
>>
>> What's the solar cell source unloaded output
>> voltage? With 600mV loaded, I'd expect >900mV?
>> If so,
>>
>>https://datasheets.maximintegrated.com/en/ds/MAX17220-MAX17225.pdf
>
> Right. Quite a few boost converters claim to
> achieve 95% under certain circumstances.
> I purchased eval boards for about 10 of them,
> but wasn't able to get better than 90% for my
> 2.0 to 2.4-volt boost. One did 92-94% at 25mW
> with 0.8 volts in, but strangely deteriorated
> at 2.0 volts in. In many cases it appeared the
> eval board inductors were too small. First,
> too low a value, and second, too much core loss.
> It seems the manufacturers just want to prove
> how small their overall used space will be.
>
> So I have footprints for about a dozen inductor
> types. I also wound an RM8-core inductor, that
> measured to fit into a 98% budget (next post),
> so I think that part of the scene is possible.
From the 2nd-page of my document on DropBox:
"98% goal: I picked an input of 0.6V. That’s a
single solar cell’s voltage, and a harder test
case. We’ll try to achieve 98% efficiency with
600mV input and 2.4V output at 10mA load = 24mW.
Boost converter freq 250kHz. An RM8 inductor,
with a low-loss 100uH winding, can work well.
Measured DCR 0.018 Ω for 0.03mW calculated loss,
and AC res 1.3 Ω, for 0.06mW loss. TS3A24159
CMOS switch, Vcc = 3.3V, for Ron 0.10 Ω, loss
0.16mW. Switching 2.4V with its Coss=150pF,
loss 0.21mW. This gives a calculated continuous
loss of 0.46mW, which is 2% of 24mW."
To compare the MAX1721: Ron 0.06 and 0.15 ohms.
The switching capacitance isn't given. With an
efficient inductor could be a winner. I haven't
the new rev of the board yet, maybe I can add it.
--
Thanks,
- Win
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Re: Achieving 98% efficiency in a boost converter, inducement Winfield Hill <hill@rowland.harvard.edu> - 2017-03-09 07:21 -0800
Re: Achieving 98% efficiency in a boost converter, inducement Winfield Hill <hill@rowland.harvard.edu> - 2017-03-09 08:29 -0800
Re: Achieving 98% efficiency in a boost converter, inducement Don Kuenz <g@crcomp.net> - 2017-03-09 21:30 +0000
Re: Achieving 98% efficiency in a boost converter, inducement Winfield Hill <hill@rowland.harvard.edu> - 2017-03-09 13:59 -0800
Re: Achieving 98% efficiency in a boost converter, inducement Winfield Hill <hill@rowland.harvard.edu> - 2017-03-10 05:30 -0800
Re: Achieving 98% efficiency in a boost converter, deadline Winfield Hill <hill@rowland.harvard.edu> - 2017-03-10 05:34 -0800
Re: Achieving 98% efficiency in a boost converter, deadline sea moss <danluster81@gmail.com> - 2017-03-10 21:10 -0800
Re: Achieving 98% efficiency in a boost converter, deadline Winfield Hill <hill@rowland.harvard.edu> - 2017-03-11 05:40 -0800
Re: Achieving 98% efficiency in a boost converter, RIS-767, new 11-page document Winfield Hill <hill@rowland.harvard.edu> - 2017-03-16 07:55 -0700
Re: Achieving 98% efficiency in a boost converter, inducement Joerg <news@analogconsultants.com> - 2017-03-16 08:08 -0700
Re: Achieving 98% efficiency in a boost converter, inducement Winfield Hill <hill@rowland.harvard.edu> - 2017-03-16 08:54 -0700
Re: Achieving 98% efficiency in a boost converter, inducement Joerg <news@analogconsultants.com> - 2017-03-16 09:36 -0700
Re: Achieving 98% efficiency in a boost converter, inducement Winfield Hill <hill@rowland.harvard.edu> - 2017-03-16 10:42 -0700
Re: Achieving 98% efficiency in a boost converter, inducement legg <legg@nospam.magma.ca> - 2017-03-19 17:58 -0400
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-03-19 15:38 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 legg <legg@nospam.magma.ca> - 2017-03-22 21:49 -0400
Re: Achieving 98% efficiency in a boost converter, RIS-767 legg <legg@nospam.magma.ca> - 2017-04-12 11:52 -0400
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-04-12 10:12 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 Joerg <news@analogconsultants.com> - 2017-04-12 10:26 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 legg <legg@nospam.magma.ca> - 2017-04-12 17:24 -0400
Re: Achieving 98% efficiency in a boost converter, RIS-767 Joerg <news@analogconsultants.com> - 2017-04-13 07:13 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-04-12 10:29 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 legg <legg@nospam.magma.ca> - 2017-04-12 17:07 -0400
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-04-13 08:22 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 legg <legg@nospam.magma.ca> - 2017-04-22 16:58 -0400
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-05-01 15:08 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-05-05 13:27 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 Don Kuenz <g@crcomp.net> - 2017-05-06 05:31 +0000
Re: Achieving 98% efficiency in a boost converter, RIS-767 dagmargoodboat@yahoo.com - 2017-05-07 14:49 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-05-08 12:05 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 sea moss <danluster81@gmail.com> - 2017-05-08 18:50 -0700
Re: Achieving 98% efficiency in a boost converter, RIS-767 Winfield Hill <hill@rowland.harvard.edu> - 2017-05-08 19:27 -0700
Re: Achieving 98% efficiency in a boost converter, inducement George Herold <gherold@teachspin.com> - 2017-03-22 19:38 -0700
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