Dumb question regarding SMPS

It saves a *lot* of time. You have to type every one in and *still* check (probably a few times by different people) to make sure you didn't make a mistake.

nuts in

exhaust on

Impossible to

widget

If there is a huge box on the page and nothing else, you are *not* describing how it works. It's no better than a netlist. Worse, actually, because you have to trace wires to find out which signals they're tied to.

a

What it's hooked to is anyone's guess, though.

A hundred blocks, perhaps. A few, not so much. Separating all the power, grounds, and JTAG, for instance, cleans up the schematic a *lot*. Breaking out the memory controller (or two - separate pages) goes a long way to readability. Perhaps all the A/Ds on a block and timers on another. There are reasonable ways to divide things up functionally. It's much like the argument for hierarchy. One big box simply sucks.

BGAs.

Nonsense. BGAs are often worth salvaging so sure there's a business in doing so. They are more difficult to replace so maybe there's a business there, too. They are *not* less reliable than QFPs. Just the opposite, in fact.

QFPs have never failed? I can tell you otherwise!

any

packages.

paycheck.

You said "record qty of five cords", implying that it was less last year.

Ouch. My heat pumps cost $.07/kWh(GA) and $.09(AL) during the heating season. My power bill approaches $200 (each place, if they were both running) during January and July. It's about half that in the off months so the heat portion of the bill is about $100 (maybe $120).

wrote

Dell's "fat

was not

not as

wonder

(does it

big

peak of

corrected)

power

too ;)

ignores

driver,

forgot

I'd

10/2.

message in

old number.

No

chose

most

error

of

built

one

busses,

but

hierarchy,

We show anything electrically connectable (like connector shell tabs, or IC power pads) as pins. Our RJ45 may have 12 pins, 8 signals and 4 grounds. We also show mounting holes on the schematic as parts, and ground them or float them.

In PADS, when you put a part on a board it imports it from the library and includes it in the current design files. If you go from, say, rev A to rev B on a schematic:pcb set, it does NOT refresh from the library unless you explicitly tell it to. So library changes don't break an existing, working design.

We have a few legacy parts with hidden VCC/ground pins (right-click to see what nets they connect to) but lately we show everything.

We never delete a part from our database, but some parts are "retired." They are physically removed from the stock room, and either disposed of, or stashed elsewhere in case engineering might want to play with a few for some reason.

It's shocking how sloppy some people are about stuff like this, about fully documenting things. But it's not a simple problem to handle revs, dash numbers, ECOs, BOMs, schematics, assembly drawings, manuals, test procedures, all that.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

wrote

Dell's "fat

was not

not as

wonder

(does it

big

peak of

corrected)

power

too ;)

ignores

driver,

forgot

I'd

10/2.

message in

old number.

No

chose

most

error

of

built

one

busses,

That usually means how many lines a bus has. Yes, some of mine have 12 lines.

but

hierarchy,

Yikes! That can quickly result in egg in the face, at the EMC lab.

If you look long enough you probably still find rectifier tubes, nuvistors and Leyden jars in there.

I bet it does. Now I am glad to be self-employed :-)

--
Regards, Joerg 

http://www.analogconsultants.com/

[...]

nuts in

exhaust on

Impossible to

widget

I see that differently. There is a uC on that page and it shows all the stuff that goes there. If I want to see the circuitry that makes MODESYNC or whatever all it takes is to go to that pages. Either that's written right next to it or one uses the find function.

a

Nope, easy to find. I never have a problem with that.

A hierarchy makes that super-simple. The uC is one big block and resides one notch above the analog stuff in the pecking order. So all you have to do is go up one hierarchy level ato see where everything connects.

BGAs.

other

six

No. I spoke to a few of those guys, wanting to know how business is going for them. Booming, they said. And none of them was salvaging any BGA, they were all repairing boards with failed BGA connections.

Thinkpads created a sizeable part of their revenue stream.

Anything with flexible leads in there generally fails less in harsh environments because there is compliance in the links. This is why I am using LFPAK FETs on the design I am working on right now. Because they have real legs on one side and the unit can poptentially be dropped onto concrete once in a while, as can just about anything.

any

packages.

paycheck.

fine.

old

I said "record qty of five cords of almond again". Big difference.

Make sure not to let too many lefties into state government. Else that will change rather quickly.

--
Regards, Joerg 

http://www.analogconsultants.com/

wrote

Dell's "fat

was not

not as

wonder

(does it

big

peak of

corrected)

power

too ;)

ignores

driver,

forgot

I'd

10/2.

message in

a

old number.

answer. No

chose

under

most

in

error

of

built

They

one

busses,

but

hierarchy,

That's the way it should be done. If anything is electrically connected it should be shown in the schematic. Mounting holes that aren't physically connected to anything I really don't care too much about. There is no other way to do LVS checking.

OrCAD does that, too. It carries all the parts along with the schematic. I never thought I'd appreciate OrCAD!

That's the right way to do it, IMO.

Nope. No way to "retire" them from the schematic database. Everything shows up the same.

It's not sloppy, at all. Sloppy says that someone isn't doing their job. In this case it's working as designed but severely broken (as designed). There is nothing we can do about it, either. ...and I haven't even scratched the surface of the idiocy, here.

wrote

Dell's "fat

was not

not as

wonder

(does it

big

peak of

corrected)

power

too ;)

ignores

driver,

forgot

I'd

10/2.

message in

a

old number.

answer. No

chose

under

most

in

error

of

built

They

one

busses,

Not how many, but their number ranges. BUSWR[0:11] would contain 12 lines named BUSWR0, BUSWR1, ...,BUSWR11. A rather unusual thing? Do you support busses within busses? Iv'e never seen that, either.

but

hierarchy,

Or worse. It could show up six months later, after the customer has already sold a million.

;-)

Wait until Obama is done with you.

nuts in

exhaust on

Impossible to

widget

OTOH, if you want to know what resources in the micro are being used to drive MODESYNC, you're screwed.

have a

How do you know what resource in the uC it's using? You have to trace it back to the pin, through an ungodly rats nest.

out

are

argument

I meant, taking the hierarchy meme to the chip level. The uC functions are part of the hierarchy.

pin BGAs.

other

package.

to

six

You must have some piss poor fab houses out there on the left coast. We've had a couple failed BGAs (fumble fingers) but that's it. I have *far* more problems with QFPs but they are easier to repair.

I've had six ThinkPads. Problems, but no BGAs. This one was a fan. The replacement, an organ replacement from my wife's old T60, didn't go so well (heat issues and I buggered up the keyboard connector).

Your theory sounds plausible but it's not reality.

any

packages.

paycheck.

fine.

old

OK? So five cords is a record and it's not? I can't decode it.

season.

No Democrats allowed. ;-) They (even Republicans can be tax and spenders) wanted to raise sales tax a penny to pay for "roads". Of course under the covers, 80% was going to mass transit and almost all of the other projects in the list had already been committed. The referendum went down 3:1. Even in the big city it went down 2:1.

wrote

Dell's "fat

was not

-- not as

wonder

arcs (does it

outlet?

big

peak of

corrected)

power

too ;)

ignores

driver,

they forgot

I'd

on 10/2.

message in

a

old number.

answer. No

chose

under

most

in

error

because of

built

never

They

one

busses,

can

but

hierarchy,

Oh, we can delete parts from the PADS library, and sometimes do. We could, but don't, delete parts from our inventory database, which is a different thing.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

wrote

Dell's "fat

was not

-- not as

wonder

arcs (does it

outlet?

big

peak of

corrected)

power

too ;)

ignores

driver,

they forgot

I'd

on 10/2.

message in

a

old number.

answer. No

chose

under

most

in

error

because of

built

never

They

one

busses,

That's probably because you've never designed an ultrasound beamformer :-)

Very normal thing there. For example, the bus CKL[0:31] contains 16 differential bus lines that go to 16 different locations, FIFOCLK[0:15] contains 16 single-ended FIFO clocks.

can

but

hierarchy,

wherever).

too.

... and one of their end users has plug it in somewhere and a building caught fire ...

He may not have another chance anymore. At least the recent polls do not look good for him.

Also, if it gets to be really bad folks like us can easily pick up stakes and move to some tropical place. Where there is no winter. Nowadays with Internet and Fedex it doesn't matter much where a consultant's office is located.

--
Regards, Joerg 

http://www.analogconsultants.com/

functional

the

nuts in

exhaust on

single

Impossible to

wanted

widget

describing

I don't need to know that from a schematic. At the beginning of a project I stake my claims to timers, PWMs, interrupt-capable pins, ADC channels and whatnot. That gets listed and goes right into my module spec before a single brush stroke happens in the schematic. I strongly believe in top-down design.

have a

I just look it up in the module spec. One reason why I use a 27" monitor. Sometimes I keep it open on the netbook to my left.

out

are

argument

I'd never, ever do that except maybe for a big fat FPGA. That can go into a hiearchy at different levels but not a uC.

pin BGAs.

not

other

package.

to

six

I don't think many of the computing devices they do BGA fixes and re-balling on where built here.

You were either lucky or very careful with them.

issues.

It is reality. It's been tested but I can't copy those docs because then I'd get shot. The failures usually happen under two test conditions, vibration and rapid temp-cycling.

PPoE

any

packages.

paycheck.

fine.

old

Record qty seen over several years. We've needed five cords the last three years. Before it was 3.5 to 4, before that 3, before that 2. Global warming at its finest.

season.

portion

Good! Wish it was the same here but people are repeatedly cajoled into voting "for the children" or whetever, and then they are being fleeced.

--
Regards, Joerg 

http://www.analogconsultants.com/

[snip]

My wife goes apoplectic every time I mention that survival mechanism, saying, "What about the grandkids"? And I reply, "Why do you think they make airplanes?" ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

wrote

Dell's "fat

arc was not

-- not as

I wonder

arcs (does it

outlet?

big

peak of

corrected)

power

lockout too ;)

ignores

driver,

they forgot

but I'd

on 10/2.

message in

tada, a

old number.

answer. No

chose

to

under

most

in

error

because of

built

Atmels,

functional

the

never

They

one

busses,

far

can

really

too, but

hierarchy,

wherever).

too.

Certainly it's a different thing. I'll bet it's marked so your purchasing can't buy it, too. These components aren't marked in any way. They're perfectly good parts, as far as the capture program is concerned.

Like I said, this is just a small part of the broken system. It's amazing that anyone is worried about the Asians.

wrote

Dell's "fat

arc was not

-- not as

I wonder

arcs (does it

outlet?

big

peak of

corrected)

power

lockout too ;)

ignores

driver,

they forgot

but I'd

on 10/2.

message in

tada, a

old number.

answer. No

chose

to

under

most

in

error

because of

built

Atmels,

functional

the

never

They

one

busses,

TOTALLY different thing. In our case, thought, we'd name them FIFOCLK0+, FIFOCLK0-, FIFOCLK1+, FIFOCLK1-.... Actually, I use a format like, Source_Function_Type[N=Negative]. But you didn't answer my question.

far

can

really

too, but

hierarchy,

schematic.

wherever).

along

too.

Yep. Guess who's fault it is, too.

makes.

Never underestimate the ignorati.

He'll tax you into oblivion before you can leave and lay claim to everything you ever make. It's the leftist's way.

that

functional

the

tires/wheels/and nuts in

exhaust on

single

Impossible to

wanted

widget

describing

You do, but what about the next guy? If you're conveying all information outside the schematic, then there's no need for a schematic. Just use a netlist.

have a

back

A rats nest is still a rats nest. A 27" monitor just makes it a bigger rats nest.

out

are

argument

You're missing my point completely. A schematic should be broken up and organized into useful parts. Hierarchy is just one tool. Another is to break large chunks into smaller bites to help readability. Many uCs and DSPs are big-fat devices. One almost fits on a D-sized print (and I print on ledger).

pin BGAs.

not

other

package.

to

six

doing

had

Whoever's doing it should be fired. It's easy stuff.

I don't consider six in ten years either. Other things broke, though. Mostly the displays. As I said, this one was the fan. BGAs certainly aren't the weak link in a laptop.

issues.

No, it certainly isn't. BGAs are *very* reliable. The military wouldn't be using them otherwise. They don't do RoHS and that's a RPITA, but they have

*no* problems with BGAs. Automotive, another harsh long-life environment, ditto.

PPoE

with any

packages.

paycheck.

thermal

office,

fine.

old

Whatever...

season.

during

portion

At least the tax-and-spenders were embarrassed into putting it up for a referendum.

that

functional

the

tires/wheels/and nuts in

exhaust on

single

Impossible to

wanted

one

widget

describing

you

drive

Strange, they all understood this kind of stuff even when they didn't have the module spec at hand. Since about 25 year. It's also how my clients always used to do it, and that's a lot of companies by now.

have a

back

Again, there is a schematic and a module spec. No ratsnest.

out

are

argument

Maybe you guys should use eyeglasses :-)

The 100PQFP I am using right now doesn't even fill 1/10th of a regular letter A here. So how many pins do yours have? 3000?

pin BGAs.

not

other

package.

try to

than six

doing

had

Fact is, lots of field failures and quite a few smart people turned this into new business opportunities.

[...]

issues.

Don't get me started on automotive electronics ...

[...]

season.

during

portion

in

Now the dems have resorted to calling taxes "fees", in order to get around the 2/3 majority requirement.

--
Regards, Joerg 

http://www.analogconsultants.com/

wrote

Dell's "fat

arc was not

-- not as

I wonder

arcs (does it

outlet?

a big

the peak of

factor corrected)

switching power

lockout too ;)

ST ignores

driver,

they forgot

but I'd

on 10/2.

message in

tada, a

the old number.

answer. No

chose

with

to

under

most

resources in

error

the

because of

already built

Atmels,

that

functional

the

never

They

as one

busses,

and

Then it's not clear to me what you mean. In ultrasound naming them like you suggest is not practical, there are simply way to many channels. So we name them like I wrote.

far

can

really

too, but

on

hierarchy,

schematic.

wherever).

along

too.

Whoever some trial lawyer pounds into settling.

makes.

Yeah :-(

Let's see what Nov-6 brings. Maybe people do wake up.

--
Regards, Joerg 

http://www.analogconsultants.com/

Same here. Plus learning yet another language isn't too appealing either. Eventually you'll have to speak Patois or at least the usual Spanish-French mix, otherwise you'll never be one of them.

There is a downside for me though. For EMC jobs on bigger equipment I often have to be on site and that's a challenge depending on location. Well, as long as a Fedex freighter gets there once a week. Some of the passenger flights I've seen there would scare the heck out of my wife. I remember an American pilot standing next to me watching an old twin-radial lumbering in. Pounding rain, lightning, fierce sidewind, the occasional flame shooting out of the exhausts. "This dude is nuts!"

--
Regards, Joerg 

http://www.analogconsultants.com/

I love DC3's. They belch flame, but somehow fly at nearly zero air-speed while landing ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

The old ones had flaming take-offs a lot:

--
Regards, Joerg 

http://www.analogconsultants.com/