Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.electronics.design > #433862

Re: 5V 200mA LDO with 0.5% accuracy

Show all headers | View raw

On 2016-11-04 16:50, John Larkin wrote:
> On Fri, 4 Nov 2016 08:33:45 -0700 (PDT), George Herold
> <gherold@teachspin.com> wrote:
>
>> On Friday, November 4, 2016 at 11:23:54 AM UTC-4, John Larkin wrote:
>>> On 3 Nov 2016 18:52:13 -0700, Winfield Hill <hill@rowland.harvard.edu>
>>> wrote:
>>>
>>>> Low-voltage devices need not apply, need 14V min.
>>>> Power package.  Would like 0.5% accuracy, but will
>>>> take 1%.  Only ON Semi's version of NSC's ancient
>>>> LP2950A, in DPak, seems to qualify.  Can this be?
>>>
>>> Do you have a voltage reference handy? An opamp, an LM317/1117 type,
>>> and a few discretes will make a good precision regulator.
>>>
>>> Sort of like this.
>>>
>>> https://dl.dropboxusercontent.com/u/53724080/Circuits/Power/Fan_Regulator.jpg
>>
>> Huh... Can you get any sort of speed out of that if you wiggle the input
>> around?  (say a few kHz.)
>
> The big output cap slows things down. The fan doesn't care. We'll
> sense PCB temp and probably do a simple slew-limited bang-bang control
> loop, basically an up-down counter.
>
> Reminds me, I've got to check that a 317 is stable with that polymer
> cap. I'll breadboard that, but I do think I have an LM317 Spice model
> around somewhere... of unknown accuracy.

LM317 should be OK. LM337 is not.

Jeroen Belleman

Back to sci.electronics.design | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

5V 200mA LDO with 0.5% accuracy Winfield Hill <hill@rowland.harvard.edu> - 2016-11-03 18:52 -0700
  Re: 5V 200mA LDO with 0.5% accuracy bill.sloman@ieee.org - 2016-11-03 20:05 -0700
  Re: 5V 200mA LDO with 0.5% accuracy Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2016-11-03 23:06 -0400
    Re: 5V 200mA LDO with 0.5% accuracy Winfield Hill <hill@rowland.harvard.edu> - 2016-11-04 06:34 -0700
      Re: 5V 200mA LDO with 0.5% accuracy speff <spehro@gmail.com> - 2016-11-04 13:46 -0700
  Re: 5V 200mA LDO with 0.5% accuracy TTman <pcw1.cad@ntlworld.com> - 2016-11-04 13:24 +0000
    Re: 5V 200mA LDO with 0.5% accuracy Winfield Hill <hill@rowland.harvard.edu> - 2016-11-04 06:43 -0700
      Re: 5V 200mA LDO with 0.5% accuracy TTman <pcw1.cad@ntlworld.com> - 2016-11-04 20:06 +0000
    Re: 5V 200mA LDO with 0.5% accuracy Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2016-11-07 09:07 -0500
  Re: 5V 200mA LDO with 0.5% accuracy Boris Mohar <borism_void_@sympatico.ca> - 2016-11-04 09:25 -0400
    Re: 5V 200mA LDO with 0.5% accuracy Winfield Hill <hill@rowland.harvard.edu> - 2016-11-04 06:53 -0700
  Re: 5V 200mA LDO with 0.5% accuracy David Brown <david.brown@hesbynett.no> - 2016-11-04 14:44 +0100
    Re: 5V 200mA LDO with 0.5% accuracy whit3rd <whit3rd@gmail.com> - 2016-11-04 11:51 -0700
  Re: 5V 200mA LDO with 0.5% accuracy John Larkin <jjlarkin@highlandtechnology.com> - 2016-11-04 08:23 -0700
    Re: 5V 200mA LDO with 0.5% accuracy George Herold <gherold@teachspin.com> - 2016-11-04 08:33 -0700
      Re: 5V 200mA LDO with 0.5% accuracy John Larkin <jjlarkin@highlandtechnology.com> - 2016-11-04 08:50 -0700
        Re: 5V 200mA LDO with 0.5% accuracy Jeroen Belleman <jeroen@nospam.please> - 2016-11-04 17:16 +0100
  Re: 5V 200mA LDO with 0.5% accuracy bloggs.fredbloggs.fred@gmail.com - 2016-11-04 11:02 -0700
    Re: 5V 200mA LDO with 0.5% accuracy Winfield Hill <hill@rowland.harvard.edu> - 2016-11-04 12:21 -0700

csiph-web