Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Computer Information > Another Newbie USB Hardware Question

Reply
Thread Tools

Another Newbie USB Hardware Question

 
 
Paul
Guest
Posts: n/a
 
      03-12-2008
Look at page 23 here:

http://www.toradex.com/downloads/Col...ics_Rev2.1.pdf


Can i replace the TPS2042 with one of these:

http://www.analogictech.com/products...es/AAT1275.pdf


???

They look to be performing the same functions, giving
the host controller an ENABLE line, and also giving an
Over-current Fault or Flag condition. So it looks like
i should be able to replace the TPS2042 with the AAT1275,
even though the former chip is only a switch, and not
a regulator too, right?


Thanks in advance....
 
Reply With Quote
 
 
 
 
Paul
Guest
Posts: n/a
 
      03-12-2008
Paul wrote:
> Look at page 23 here:
>
> http://www.toradex.com/downloads/Col...ics_Rev2.1.pdf
>
>
> Can i replace the TPS2042 with one of these:
>
> http://www.analogictech.com/products...es/AAT1275.pdf
>
>
> ???
>
> They look to be performing the same functions, giving
> the host controller an ENABLE line, and also giving an
> Over-current Fault or Flag condition. So it looks like
> i should be able to replace the TPS2042 with the AAT1275,
> even though the former chip is only a switch, and not
> a regulator too, right?
>
>
> Thanks in advance....


I'm all for helping you, but the thing is, this isn't how
you approach engineering. You look at all the requirements,
and then decide how the existing design meets those requirements,
and which parts have to be changed. Or whether, in fact, the
Colibri is so far removed from what you want to do, to be a
poor starting point.

Your question implies a change to the power distribution system.
As if, certain rails are not available to the thing you are
trying to design. You need to examine all the subsystems,
their power requirements. Also, why the designer of the
existing design, chose to do his power conversion and
distribution in a particular way. You make a list of all
the power requirements for the design, and *then* make
the call as to where to put boost or buck converters etc.
Maybe if other parts of the design need +5V, you need a
bigger converter.

You'll save yourself a lot of work, if you study the design
first, and save schematic edits, for when all of your planning
is finished. Making a change here, and a change there, may not
cut it. And would be the mark of an amateur.

The AAT1275 implies you want to run a USB port, off a battery.
It seems a rather radical shift, and suggests you're about
to pepper us with 20 more, context free, component change
requests.

Also, I expect you'll soon be asking "can anybody pick out
a 2.2uH inductor for me?". The answer to that is "No".
I hate picking inductors for stuff. Page 11 of the datasheet,
goes through some of the technical issues. For the more
complex boost or buck switchers, some designers prototype
the design first, and optimize it (perhaps changing inductors,
if they don't like how the prototype is behaving). In this
case, since the output of the AAT1275 is not powering a part
of the main board, you could use the design itself as your
prototyping platform, paying for your mistakes with a PCB respin.

Some component manufacturers, make available evaluation boards,
and maybe you could get an eval board with the AAT1275 on it.
The advantage there, is you'd get to see the inductor they
chose, and also have a platform for testing the circuit before
using it. (Loading the thing up to 500mA, and seeing whether
it regulates properly.) Of course, an eval board costs money.

What happens with some switching converter designs, is the
designer poorly estimates the power requirements of the
load, and the switching converter is optimized for one
particular load point. Suddenly, the designer discovers
what a poor choice the thing is, because it is so close
to overload, or not being able to drive the load. I can't
speak to the AAT1275, and how well it does its job, but
adding a component like that to a design, increase the
"risk" factor.

Paul
 
Reply With Quote
 
 
 
 
CBFalconer
Guest
Posts: n/a
 
      03-12-2008
Paul wrote: ((E-Mail Removed))
> Paul wrote: ((E-Mail Removed))


One (or both) of you needs a more descriptive name.

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home.att.net>
Try the download section.



--
Posted via a free Usenet account from http://www.teranews.com

 
Reply With Quote
 
Paul
Guest
Posts: n/a
 
      03-12-2008
On Mar 11, 7:38 pm, Paul <(E-Mail Removed)> wrote:
> Paul wrote:
> > Look at page 23 here:

>
> >http://www.toradex.com/downloads/Col...d_Schematics_R...

>
> > Can i replace the TPS2042 with one of these:

>
> > http://www.analogictech.com/products...es/AAT1275.pdf

>
> > ???

>
> > They look to be performing the same functions, giving
> > the host controller an ENABLE line, and also giving an
> > Over-current Fault or Flag condition. So it looks like
> > i should be able to replace the TPS2042 with the AAT1275,
> > even though the former chip is only a switch, and not
> > a regulator too, right?

>
> > Thanks in advance....

>
> I'm all for helping you, but the thing is, this isn't how
> you approach engineering. You look at all the requirements,
> and then decide how the existing design meets those requirements,
> and which parts have to be changed. Or whether, in fact, the
> Colibri is so far removed from what you want to do, to be a
> poor starting point.
>
> Your question implies a change to the power distribution system.
> As if, certain rails are not available to the thing you are
> trying to design. You need to examine all the subsystems,
> their power requirements. Also, why the designer of the
> existing design, chose to do his power conversion and
> distribution in a particular way. You make a list of all
> the power requirements for the design, and *then* make
> the call as to where to put boost or buck converters etc.
> Maybe if other parts of the design need +5V, you need a
> bigger converter.
>
> You'll save yourself a lot of work, if you study the design
> first, and save schematic edits, for when all of your planning
> is finished. Making a change here, and a change there, may not
> cut it. And would be the mark of an amateur.
>
> The AAT1275 implies you want to run a USB port, off a battery.
> It seems a rather radical shift, and suggests you're about
> to pepper us with 20 more, context free, component change
> requests.
>
> Also, I expect you'll soon be asking "can anybody pick out
> a 2.2uH inductor for me?". The answer to that is "No".
> I hate picking inductors for stuff. Page 11 of the datasheet,
> goes through some of the technical issues. For the more
> complex boost or buck switchers, some designers prototype
> the design first, and optimize it (perhaps changing inductors,
> if they don't like how the prototype is behaving). In this
> case, since the output of the AAT1275 is not powering a part
> of the main board, you could use the design itself as your
> prototyping platform, paying for your mistakes with a PCB respin.
>
> Some component manufacturers, make available evaluation boards,
> and maybe you could get an eval board with the AAT1275 on it.
> The advantage there, is you'd get to see the inductor they
> chose, and also have a platform for testing the circuit before
> using it. (Loading the thing up to 500mA, and seeing whether
> it regulates properly.) Of course, an eval board costs money.
>
> What happens with some switching converter designs, is the
> designer poorly estimates the power requirements of the
> load, and the switching converter is optimized for one
> particular load point. Suddenly, the designer discovers
> what a poor choice the thing is, because it is so close
> to overload, or not being able to drive the load. I can't
> speak to the AAT1275, and how well it does its job, but
> adding a component like that to a design, increase the
> "risk" factor.
>
> Paul



Ok, now will someone with REAL knowledge/experience
in USB chime in and actually answer my question?


 
Reply With Quote
 
Paul
Guest
Posts: n/a
 
      03-12-2008
Paul wrote:
> On Mar 11, 7:38 pm, Paul <(E-Mail Removed)> wrote:
>> Paul wrote:
>>> Look at page 23 here:
>>> http://www.toradex.com/downloads/Col...d_Schematics_R...
>>> Can i replace the TPS2042 with one of these:
>>> http://www.analogictech.com/products...es/AAT1275.pdf
>>> ???
>>> They look to be performing the same functions, giving
>>> the host controller an ENABLE line, and also giving an
>>> Over-current Fault or Flag condition. So it looks like
>>> i should be able to replace the TPS2042 with the AAT1275,
>>> even though the former chip is only a switch, and not
>>> a regulator too, right?
>>> Thanks in advance....

>> I'm all for helping you, but the thing is, this isn't how
>> you approach engineering. You look at all the requirements,
>> and then decide how the existing design meets those requirements,
>> and which parts have to be changed. Or whether, in fact, the
>> Colibri is so far removed from what you want to do, to be a
>> poor starting point.
>>
>> Your question implies a change to the power distribution system.
>> As if, certain rails are not available to the thing you are
>> trying to design. You need to examine all the subsystems,
>> their power requirements. Also, why the designer of the
>> existing design, chose to do his power conversion and
>> distribution in a particular way. You make a list of all
>> the power requirements for the design, and *then* make
>> the call as to where to put boost or buck converters etc.
>> Maybe if other parts of the design need +5V, you need a
>> bigger converter.
>>
>> You'll save yourself a lot of work, if you study the design
>> first, and save schematic edits, for when all of your planning
>> is finished. Making a change here, and a change there, may not
>> cut it. And would be the mark of an amateur.
>>
>> The AAT1275 implies you want to run a USB port, off a battery.
>> It seems a rather radical shift, and suggests you're about
>> to pepper us with 20 more, context free, component change
>> requests.
>>
>> Also, I expect you'll soon be asking "can anybody pick out
>> a 2.2uH inductor for me?". The answer to that is "No".
>> I hate picking inductors for stuff. Page 11 of the datasheet,
>> goes through some of the technical issues. For the more
>> complex boost or buck switchers, some designers prototype
>> the design first, and optimize it (perhaps changing inductors,
>> if they don't like how the prototype is behaving). In this
>> case, since the output of the AAT1275 is not powering a part
>> of the main board, you could use the design itself as your
>> prototyping platform, paying for your mistakes with a PCB respin.
>>
>> Some component manufacturers, make available evaluation boards,
>> and maybe you could get an eval board with the AAT1275 on it.
>> The advantage there, is you'd get to see the inductor they
>> chose, and also have a platform for testing the circuit before
>> using it. (Loading the thing up to 500mA, and seeing whether
>> it regulates properly.) Of course, an eval board costs money.
>>
>> What happens with some switching converter designs, is the
>> designer poorly estimates the power requirements of the
>> load, and the switching converter is optimized for one
>> particular load point. Suddenly, the designer discovers
>> what a poor choice the thing is, because it is so close
>> to overload, or not being able to drive the load. I can't
>> speak to the AAT1275, and how well it does its job, but
>> adding a component like that to a design, increase the
>> "risk" factor.
>>
>> Paul

>
>
> Ok, now will someone with REAL knowledge/experience
> in USB chime in and actually answer my question?
>


Yes, you can use it.

Next question.

Paul

 
Reply With Quote
 
David Brown
Guest
Posts: n/a
 
      03-12-2008
Paul wrote:
> On Mar 11, 7:38 pm, Paul <(E-Mail Removed)> wrote:
>> Paul wrote:
>>> Look at page 23 here:
>>> http://www.toradex.com/downloads/Col...d_Schematics_R...
>>> Can i replace the TPS2042 with one of these:
>>> http://www.analogictech.com/products...es/AAT1275.pdf
>>> ???


<snip>

>> I'm all for helping you, but the thing is, this isn't how
>> you approach engineering. You look at all the requirements,
>> and then decide how the existing design meets those requirements,
>> and which parts have to be changed. Or whether, in fact, the
>> Colibri is so far removed from what you want to do, to be a
>> poor starting point.
>>


<snip a lot of useful advice>

>> Paul

>
>
> Ok, now will someone with REAL knowledge/experience
> in USB chime in and actually answer my question?
>


Is it just me, or does this guy Paul Quiller represent a new low with
his antisocial responses?

Paul Nospam clearly spent a fair amount giving you (Paul Quiller)
helpful advice, both in this thread and a previous thread. In both
threads, when you couldn't understand the help you were given, you
responded by insulting the poster. You don't just need to go back to
college and learn how to do electronics engineering (hint - it's not
just cutting and pasting from evaluation cards) - you need to go back to
kindergarten and learn how to play nicely with other children.


 
Reply With Quote
 
Chris H
Guest
Posts: n/a
 
      03-12-2008
In message <47d79490$0$14989$(E-Mail Removed)>, David Brown
<(E-Mail Removed)> writes
>Paul wrote:
>> On Mar 11, 7:38 pm, Paul <(E-Mail Removed)> wrote:
>>> Paul wrote:
>>>> Look at page 23 here:
>>>> http://www.toradex.com/downloads/Col...d_Schematics_R...
>>>> Can i replace the TPS2042 with one of these:
>>>> http://www.analogictech.com/products...es/AAT1275.pdf
>>>> ???

>
><snip>
>
>>> I'm all for helping you, but the thing is, this isn't how
>>> you approach engineering. You look at all the requirements,
>>> and then decide how the existing design meets those requirements,
>>> and which parts have to be changed. Or whether, in fact, the
>>> Colibri is so far removed from what you want to do, to be a
>>> poor starting point.
>>>

>
><snip a lot of useful advice>
>
>>> Paul

>> Ok, now will someone with REAL knowledge/experience
>> in USB chime in and actually answer my question?
>>

>
>Is it just me, or does this guy Paul Quiller represent a new low with
>his antisocial responses?


Not quite... the new low is that I am going to have to publicly agree
with you again

>Paul Nospam clearly spent a fair amount giving you (Paul Quiller)
>helpful advice, both in this thread and a previous thread. In both
>threads, when you couldn't understand the help you were given, you
>responded by insulting the poster. You don't just need to go back to
>college and learn how to do electronics engineering (hint - it's not
>just cutting and pasting from evaluation cards) - you need to go back
>to kindergarten and learn how to play nicely with other children.


This is getting more common. There have been a couple of threads where
new people have also said I don't care about the social norms and
"rules" of this group I am going to do my own thing and if you don't
like it you can go away.

It is one thing old hands arguing for a change but newbies who don't
know how and why things have developed the way they have just seem to be
diving in with no social graces at all. You can tell the don't get out
enough because if they behaved that way in a bar they would be in
hospital more than the bar!

The other thing is that many do not bother to look in the manuals much
less the online help at the tool/chip vendors web site.

How come they can find this group on Usenet (ITS NOT A GOOGLE GROUP
Google is just the front end viewer) but cant search the Internet
intelligently?

I can recall back in the mid 1990's when AOL dumped its people onto the
net thereby causing AOL users to be known as Arse-holes On Line. Now it
seems that every halfwit and social miss-fit can find there way here and
behave in a way they could not in a real social interaction.

Incidentally David I had already drafted most of my next ESE column on
this very subject. It seems to have got a lot worse over the last few
months. Perhaps it is just the socially inadequate have coincided with
a new term at collage and we seem to be having more of them.

I recall some one else had a go about this a year back?

--
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills Staffs England /\/\/\/\/
/\/\/ http://www.velocityreviews.com/forums/(E-Mail Removed) www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/



 
Reply With Quote
 
Chris H
Guest
Posts: n/a
 
      03-12-2008
In message
<(E-Mail Removed)>,
Paul <(E-Mail Removed)> writes
>On Mar 11, 7:38 pm, Paul <(E-Mail Removed)> wrote:
>> Paul wrote:
>> > Look at page 23 here:

>>
>> >http://www.toradex.com/downloads/Col...d_Schematics_R...

>>
>> > Can i replace the TPS2042 with one of these:

>>
>> > http://www.analogictech.com/products...es/AAT1275.pdf

>>
>> > ???

>>
>> > They look to be performing the same functions, giving
>> > the host controller an ENABLE line, and also giving an
>> > Over-current Fault or Flag condition. So it looks like
>> > i should be able to replace the TPS2042 with the AAT1275,
>> > even though the former chip is only a switch, and not
>> > a regulator too, right?

>>
>> > Thanks in advance....

>>
>> I'm all for helping you, but the thing is, this isn't how
>> you approach engineering. You look at all the requirements,

]
....................


>> adding a component like that to a design, increase the
>> "risk" factor.
>>
>> Paul

>
>
> Ok, now will someone with REAL knowledge/experience
>in USB chime in and actually answer my question?


I think that was the wrong answer to some good advice.


--
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills Staffs England /\/\/\/\/
/\/\/ (E-Mail Removed) www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/



 
Reply With Quote
 
John Devereux
Guest
Posts: n/a
 
      03-12-2008
Chris H <(E-Mail Removed)> writes:

> In message <47d79490$0$14989$(E-Mail Removed)>, David Brown
> <(E-Mail Removed)> writes
>>Paul wrote:
>>> On Mar 11, 7:38 pm, Paul <(E-Mail Removed)> wrote:
>>>> Paul wrote:
>>>>> Look at page 23 here:
>>>>> http://www.toradex.com/downloads/Col...d_Schematics_R...
>>>>> Can i replace the TPS2042 with one of these:
>>>>> http://www.analogictech.com/products...es/AAT1275.pdf
>>>>> ???

>>
>><snip>
>>
>>>> I'm all for helping you, but the thing is, this isn't how
>>>> you approach engineering. You look at all the requirements,
>>>> and then decide how the existing design meets those requirements,
>>>> and which parts have to be changed. Or whether, in fact, the
>>>> Colibri is so far removed from what you want to do, to be a
>>>> poor starting point.
>>>>

>>
>><snip a lot of useful advice>
>>
>>>> Paul
>>> Ok, now will someone with REAL knowledge/experience
>>> in USB chime in and actually answer my question?
>>>

>>
>> Is it just me, or does this guy Paul Quiller represent a new low
>> with his antisocial responses?


On s.e.d.? I think I can safely say we've gone lower!

But I agree, it's pretty bad - the worst I can recall in
comp.arch.embedded actually.

> Not quite... the new low is that I am going to have to publicly agree
> with you again
>
>> Paul Nospam clearly spent a fair amount giving you (Paul Quiller)
>> helpful advice, both in this thread and a previous thread. In both
>> threads, when you couldn't understand the help you were given, you
>> responded by insulting the poster. You don't just need to go back
>> to college and learn how to do electronics engineering (hint - it's
>> not just cutting and pasting from evaluation cards) - you need to go
>> back to kindergarten and learn how to play nicely with other
>> children.

>
> This is getting more common. There have been a couple of threads
> where new people have also said I don't care about the social norms
> and "rules" of this group I am going to do my own thing and if you
> don't like it you can go away.
>
> It is one thing old hands arguing for a change but newbies who don't
> know how and why things have developed the way they have just seem to
> be diving in with no social graces at all. You can tell the don't
> get out enough because if they behaved that way in a bar they would be
> in hospital more than the bar!
>
> The other thing is that many do not bother to look in the manuals much
> less the online help at the tool/chip vendors web site.
>
> How come they can find this group on Usenet (ITS NOT A GOOGLE GROUP
> Google is just the front end viewer) but cant search the Internet
> intelligently?
>
> I can recall back in the mid 1990's when AOL dumped its people onto
> the net thereby causing AOL users to be known as Arse-holes On Line.
> Now it seems that every halfwit and social miss-fit can find there way
> here and behave in a way they could not in a real social interaction.
>
> Incidentally David I had already drafted most of my next ESE column on
> this very subject. It seems to have got a lot worse over the last few
> months. Perhaps it is just the socially inadequate have coincided
> with a new term at collage and we seem to be having more of them.
>
> I recall some one else had a go about this a year back?


See "the September that never ended"

<http://en.wikipedia.org/wiki/Eternal_September>

--

John Devereux
 
Reply With Quote
 
sky465nm@trline4.org
Guest
Posts: n/a
 
      03-12-2008
>> Incidentally David I had already drafted most of my next ESE column on

url?

>> this very subject. It seems to have got a lot worse over the last few
>> months. Perhaps it is just the socially inadequate have coincided
>> with a new term at collage and we seem to be having more of them.
>>
>> I recall some one else had a go about this a year back?


>See "the September that never ended"


><http://en.wikipedia.org/wiki/Eternal_September>


Well if schools allow first 16-18 year olds (college). Then add 13-15 years
old aswell (elementary). And add millions of people without academic connection
whatsoever from the strict commercial sphere. The end result can't be an
suprise. Can't say 99% of the people in elementary I came as across as even
trying to have reflection over matters or vision. And now they creeped back in.

 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Plug-in USB hardware device captures keystrokes on Mac and PC USB keyboards. Theo Computer Security 15 12-06-2012 02:10 AM
Another Question: Java and other application, Java and hardware Roberto Faenza Java 4 02-25-2007 06:18 PM
Re: USB issue ... some USB 2 ports working only in USB 1 mode hungsolo2005@yahoo.com A+ Certification 0 06-14-2006 07:26 PM
another newbie question from another newbie.... Lee UK VOIP 4 05-17-2005 04:10 PM
Does a DSL USB modem serve as a hardware firewall? Jimmy Dean Computer Support 7 10-13-2004 01:34 PM



Advertisments