[SI-LIST] Re: LDO power supply vs DC-DC switching supply
- From: Faraydon Pakbaz <pakbazf@xxxxxxxxxx>
- To: gnuarm.2006@xxxxxxxxx
- Date: Fri, 2 Aug 2013 13:50:02 -0400
Hi Rick;
First many thanks for taking time and explaining the difference. It seems
the trade-off comes down to
power consumption and heat. Do I get that correctly?
For example if one try to route crystal Oscillator at the board level with
number of buffering stages
and branches at the board level and use LDO then it is possible that excess
heat, efficiency maybe
an issue?!
Regards;
Don Pakbaz
|------------>
| From: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|Rick Collins <gnuarm.2006@xxxxxxxxx>
|
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| To: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|si-list@xxxxxxxxxxxxx,
|
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Date: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|08/02/2013 01:10 PM
|
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Subject: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|[SI-LIST] Re: LDO power supply vs DC-DC switching supply
|
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Sent by: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|si-list-bounce@xxxxxxxxxxxxx
|
>--------------------------------------------------------------------------------------------------------------------------------------------------|
LDO (or more correctly, linear) regulators act as high pass filters
with a lower pass frequency around the 100 kHz ballpark The noise
rejection not too far above 100 kHz can approach just -10 dB. Some
units have poor line regulation in the higher end of the audio
region. Switching regulators have most of their noise at high
frequencies. "High" depends on the unit with some switching around
50 kHz up to several MHz. There is a lot of harmonic content at
frequencies higher than the switching rate and there can be some
content at lower frequencies if the units "hunt" or "motorboat" as
they regulate (this is not generally considered correct operation,
but is sometimes tolerated).
To damn switching regulators because they emit noise can be overly
broad depending on your application. If you are designing an HF
radio receiver, then you likely don't want any switchers you don't
have to have. For many other applications swtichers will work just
fine if you pay careful attention to the details of noise
mitigation. It mostly depends on the frequency range your design is
sensitive to. Switchers are normally used when the power dissipation
of a linear regulator would be too high.
Rick
At 12:32 PM 8/2/2013, steve weir wrote:
>In general the answer is yes. A switching power supply in very
>simplistic terms: the switching superimposes a carrier on top of the
>normal regulator output that then requires filtering to remove. Hard
>switching converters are simple and cheap, and tend to be the worst
>offenders. However, there are switchers that are very quiet whether by
>brute force filtering and/or that use soft switching. It shouldn't be
>surprising to learn that the latter cost more money.
>
>Steve
>On 8/2/2013 8:50 AM, Faraydon Pakbaz wrote:
> > Greetings SI experts;
> >
> > Is LDO (Low drop out) power supply, less nosier than DC-DC switching
power
> > supply type?
> > Are there application trade-offs between these two types of supply?
Thanks
> > in advance for
> > your advise and comments.
> >
> > Regards;
> >
> > Don Pakbaz
> >
> >
> > ------------------------------------------------------------------
> > To unsubscribe from si-list:
> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
> >
> > or to administer your membership from a web page, go to:
> > //www.freelists.org/webpage/si-list
> >
> > For help:
> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
> >
> >
> > List forum is accessible at:
> > http://tech.groups.yahoo.com/group/si-list
> >
> > List archives are viewable at:
> > //www.freelists.org/archives/si-list
> >
> > Old (prior to June 6, 2001) list archives are viewable at:
> > http://www.qsl.net/wb6tpu
> >
> >
> >
>
>
>--
>Steve Weir
>IPBLOX, LLC
>1580 Grand Point Way
>MS 34689
>Reno, NV 89523-9998
>www.ipblox.com
>
>(775) 299-4236 Business
>(866) 675-4630 Toll-free
>(707) 780-1951 Fax
>
>All contents Copyright (c)2013 IPBLOX, LLC. All Rights Reserved.
>This e-mail may contain confidential material.
>If you are not the intended recipient, please destroy all records
>and notify the sender.
>
>------------------------------------------------------------------
>To unsubscribe from si-list:
>si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
>or to administer your membership from a web page, go to:
>//www.freelists.org/webpage/si-list
>
>For help:
>si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>
>List forum is accessible at:
> http://tech.groups.yahoo.com/group/si-list
>
>List archives are viewable at:
> //www.freelists.org/archives/si-list
>
>Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
>
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
