17V@7A switching power supply

[Clarence]

Of course it isn't what he wanted. He wanted:

For a better understanding, just look at these lines:


Notice the important part:

Which probably means:
"just in one package".
"one" as in "single".

Gee, I thought he wanted something that worked! The circuit meets the
electrical specification.

But the circuit from Linear CAN be put in ONE package! At 95% efficiency
(predicted) makes it reasonable to put it in a rather small foot print. Also,
he will still need the support circuitry and filter Caps so it is not a lot
different.

Since you are not an Engineer I guess you wouldn't know there are few to none
which can handle a 14 ampere bilateral switch in one IC package. Cost and
power are both high.

I'll wait for the OP to decide.

BTW, I have used a lot of LM2678's.

 

[John Fields]

As usual, ran off at the mouth, spreading foul and nasty things which he is so
familiar with.

He is about to burst a blood vessel and can not seem to control himself.

Besides he has a mean streak a mile wide.

Spicewood club? Funny name.

Are all the people there like you?
No don't answer, you need to relax and get some sleep.

See your doctor soon, he will give you something to calm your nerves and let
you sleep.

Wow. I never though walking the dog could be so exhausting!

 

[John Fields]

Okay, weak mind, poor to no control, the usual ilk of someone with megalomania.

---
What does that have to do with you "having" my design?
---

The foul mouth is properly labeled!

---
More cut and paste?

I'll bet your mommy won't let you use pointy scissors though, and I'll
bet she gets pissed when you scribble all over the walls with crayons.
---

I didn't say I 'did' the design, I sent it to him.

---
That's not the point. he asked for help, not for URLs. Any idiot (as
you've proven, many times) can look around and find something vaguely
related to the subject at hand and paste the URL where he found it. A
real no-brainer, and nothing like asking for spec's and then figuring
out how to put something together, from scratch, which will provide an
adequate answer to the poster's question.
---

I don't work for free like you.

---
Of course you don't. Greedy, money-grubbing worms like you _can't_
because you equate pecuniary gain with happiness and you think that if
you do _anything_ for free you've been taken advantage of.
---

Wow, walking the dog is getting tiring!

---
That's because the dog is bigger than you are and is pulling you
around wherever he wants to go! _You're- the one who's being walked,
imbecile.

 

[Anders F]

I still recommend separate mosfets! But of course Hassan /might/ actually
mean what he wrote. He might look at Sipex's offerings... (ie. SP7655 8A
buck to 28V). That is if he's actually following the discussion ;-)

/Anders

 

[Hassan]

Did you get my schematic?
Is it along the lines of what you wanted?

No; I could find the link to a power supply. If you have schematic,
please give me its URL or any other way that I can access it.
Thank you
Hassan

 

[Frank Bemelman]

I still recommend separate mosfets! But of course Hassan /might/ actually
mean what he wrote. He might look at Sipex's offerings... (ie. SP7655 8A
buck to 28V). That is if he's actually following the discussion ;-)

I'm surprised that one exists. Small package too, 7mm x 4mm. It
looks challenging to get rid of the heat, even at 95% efficiency.

 

[Clarence]

I know, are your singing yet?

I didn't think so!

 

[Clarence]

---
That's not the point. he asked for help, not for URLs. Any idiot (as
you've proven, many times) can look around and find something vaguely
related to the subject at hand and paste the URL where he found it. A
real no-brainer, and nothing like asking for spec's and then figuring
out how to put something together, from scratch, which will provide an
adequate answer to the poster's question.

I pointed him at a possible single packaged Power supply to meet his needs.

I also posted a schematic of a circuit for him, for comment. Your interference
has prevented him from replying.

---
Of course you don't. Greedy, money-grubbing worms like you _can't_
because you equate pecuniary gain with happiness and you think that if
you do _anything_ for free you've been taken advantage of.
---

The spell it PROFESSIONAL!
But you wouldn't know anything about THAT would you?

---
---
I'll do what I damn well please, and if you find that the headwind is
too strong for you, then I suggest you save yourself some grief and
learn how to tack.
--

Spoken like a real nut!
I can Tack and Reach. Any point of sail.

I consider you to be a minor disturbance and of no value whatever.

 

[Clarence]

Did you get my schematic?
Is it along the lines of what you wanted?

No; I could find the link to a power supply. If you have schematic,
please give me its URL or any other way that I can access it.
Thank you
Hassan[/QUOTE]

It is in a binary group.
alt.binaries.schematics.electronic

Title is
24 volt in, 15 volt @ 7 amperes out. As requested.

Pretty much self explanatory.

 

[Clarence]

It is in a binary group.
alt.binaries.schematics.electronic

Title is
24 volt in, 15 volt @ 7 amperes out. As requested.

Pretty much self explanatory.

By the way. You can download "SwitcherCAD" free from Linear's web site.

http://www.linear.com/index.jsp

I am in no way associated with this company.

 

[ChrisGibboGibson]

:

[snip]

By the way. You can download "SwitcherCAD" free from Linear's web site.

http://www.linear.com/index.jsp

I am in no way associated with this company.

And if, by some strange freak event, you became so, they would, in all
probability, deny it.

Gibbo

 

[John Fields]

I pointed him at a possible single packaged Power supply to meet his needs.

---
That's not what he asked for, but of course you know better than he
does what he wants.
---

I also posted a schematic of a circuit for him, for comment. Your interference
has prevented him from replying.

---
Really? In what way? Did that little mind of yours forget to tell
him where it was because it was all filled up with you trying to
figure out the simple logic I hit you with?
---

The spell it PROFESSIONAL!
But you wouldn't know anything about THAT would you?

---
LOL!!!
Not only are you a fucking idiot, you're a fucking idiot as well!
And you say you're a teacher? God help those poor folks who you
manage to fool into thinking you know what you're talking about.
---

 

[Anders F]

I'm surprised that one exists. Small package too, 7mm x 4mm. It
looks challenging to get rid of the heat, even at 95% efficiency.

Say 8A @ 30mR (didn't check the actual value) - that's under 2W...
And powerplanes/copper fills are quite effective heat-spreaders (try solder
a plane with a tiny tip ;-)

/Anders

 

[John Fields]

http://www.linear.com/index.jsp

I am in no way associated with this company.

 

[Clarence]

I'm surprised that one exists. Small package too, 7mm x 4mm. It
looks challenging to get rid of the heat, even at 95% efficiency.

Say 8A @ 30mR (didn't check the actual value) - that's under 2W...
And powerplanes/copper fills are quite effective heat-spreaders (try solder
a plane with a tiny tip ;-)

/Anders

The App note shows 16 components external and it is a sole source part.

At least the alternate with external Power switches did not take so many
additional parts and there are other sources for a similar component.

Price comparisons?

 

[John Fields]

It is in a binary group.
alt.binaries.schematics.electronic

Title is
24 volt in, 15 volt @ 7 amperes out. As requested.

Pretty much self explanatory.

 

[Hassan]

I still recommend separate mosfets! But of course Hassan /might/ actually
mean what he wrote. He might look at Sipex's offerings... (ie. SP7655 8A
buck to 28V). That is if he's actually following the discussion ;-)

/Anders

Thank you very much for your reply.
It seems that this IC is optimized for 5 V DC output. In my
application, the input voltage rises to 30 VDC and its down margin is
20 V DC. The maximum input voltage for SP7655 is 28 V DC. Do you know
another IC which can support what I need? I need a switching power
supply IC (the controller and the power mosfet in just one package) to
make a switching power supply with the specifications of:
Input voltage less than 30 V DC and greater than 20 V DC.
Output voltage 15 V @ 7 A.

In case of not finding such an IC, any design recommendations with
high efficiency (greater than 85%) would be greatly appreciated.
I am looking forward to hearing.
Thank you in advance.
Hassan

 

[Clarence]

Hassan wrote:
Hello;
I want to design a switching power supply with:
Vin=24 Vdc and Vo=15V @ 7A

Notice the important part:
controller and power Mosfet just in a package.

<snip>

In case of not finding such an IC, any design recommendations with
high efficiency (greater than 85%) would be greatly appreciated.
I am looking forward to hearing.
Thank you in advance.
Hassan


I Recommend!
LTC1775 By Linear Technology
95% efficiency! Best I found for this spec.

Schematic in S.E.C. under
"24 volt in, 15 volt @ 7 amperes out. As requested."

13 external components, total. IC is a SOIC8 Plus two Fet switches. Small
over all.

 

[Anders F]

I'm surprised that one exists. Small package too, 7mm x 4mm. It
looks challenging to get rid of the heat, even at 95% efficiency.

Say 8A @ 30mR (didn't check the actual value) - that's under 2W...
And powerplanes/copper fills are quite effective heat-spreaders (try solder
a plane with a tiny tip ;-)

/Anders

The App note shows 16 components external

True. This is not uncommon though... Flexibility cost!

and it is a sole source part.

I find very few switchers with second sources...

At least the alternate with external Power switches did not take so many
additional parts

They're available yes! And probably cheaper as Sipex are the first with
integrated fets in those currents. I've asked for a price though - I might
actually use it as I can use every mm2 I can get ;-)

and there are other sources for a similar component.

Similar - but not compatible. Not much better than a single-source to me!

Price comparisons?

Patience my friend ;-)

Cheers,
Anders

 

[Anders F]

Thank you very much for your reply.
It seems that this IC is optimized for 5 V DC output. In my
application, the input voltage rises to 30 VDC and its down margin is
20 V DC.

Fair enough! You still fail to state why the integrated fets are important.
If it's space you'll be in problems with the coils for high efficiency
designs anyway. Don't take the 95% for granted - carefull selection of (big)
coils and (expensive) fet's/diodes are usually required!

The maximum input voltage for SP7655 is 28 V DC. Do you know
another IC which can support what I need? I need a switching power
supply IC (the controller and the power mosfet in just one package)

I gave you the only one I know of for high current!
With external fets it's another story:

to
make a switching power supply with the specifications of:
Input voltage less than 30 V DC and greater than 20 V DC.
Output voltage 15 V @ 7 A.

Lots of possible designs from TI, Linear, Maxim, National and so on. Others
made recommendations...

Cheers,
Anders