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Any beefy coil driver chips?

[snip]

I often resort to asking the client, "Measure this, measure that, under these conditions..."

I only tell the client they are stupid if they get belligerent. If they persist, I tell them to get someone else. Amazing how many come back... often _years_ and _millions_of_dollars_ later, to have me redo their chip design ;-)

Admittedly, Joerg is often dealing with medical types. When I wrote up an instruction manual for blood flow apparatus I built as my Bachelor's thesis (joint MIT and Harvard School of Medicine), I had my wife proof read it. Her comment, "It's seems at an awfully juvenile level". I told her it was necessary when dealing with doctors ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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     |

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Reply to
Jim Thompson
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Those look good, though Joerg implies he has no other power than the "24V" when it's applied.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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     |
       
    All that is necessary for the triumph of evil
            is that good men do nothing. 
                  -Edmund Burke
Reply to
Jim Thompson

Thanks, Win. Very interesting chip. However, for an initial continuous on state of the upper FET the boost cap won't come up because for some reason they just hung that onto the drive for the lower FET. But there may be options with connecting the coil to V+. Makes current sense on it a bear though.

Do you know which market they normally serve? The data sheet is a bit mum about that. What's really nice is that the chip goes to 100kHz. Should be high enough to muffle conducted noise at least to some extent. If I don't they'd read me the riot act ;-)

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Regards, Joerg

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Reply to
Joerg

Thanks, Ross. Vcesat looks highish though. The PLCC pack is the only one I could fit and it would probably unsolder itself ;-)

Well, not literally since it has a shutdown funtion but that would be quite disruptive as well.

Yep, only that switched line plus the usual spikes, surges and such on it. If I had enough real estate I'd be almost home. Same if I had unfettered access to a nice HV foundry, plus a wad of cash to pay for masks and NRE :-)

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Regards, Joerg

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Joerg

k

I'm assuming you'd drive the coil to ground. That way you start out with the output low and with the coil off, and at that time the hi- side flying cap gets charged, ready for your first turn-on.

A fixed duty-cycle PWM half-bridge setup can be seen as an unregulated DC transformer, and there are potentially many types of applications for that. IR actually has an entire series of similar parts. Their press release claimed the 2153 was meant for flourescent bulb ballasts. But it seems inadequate to the task to me. Their newer ICs, such as the IRS2530, do more of the job, which is fairly complicated.

Reply to
Winfield Hill

Actually I must ramp the coil current to the hilt the instant the rail comes up. In cases like this the rail is the switched line and also the only power source. Wanting an extra DC power line to come in is almost like renting a backhoe and starting to trench :-)

I have to go through their stuff one more time, maybe they really have something useful. Usually Supertex comes to the rescue in such cases but not this time. They have only the HV9901 and it wouldn't buy me that much in space savings versus discretes. OTOH, cost is not the driving factor on this design, within reason, meaning no chip design. Ain't that nice for a change?

Sometimes I envy guys like Jim but I had that luxury only twice: You shop around for HV processes and then piece it all together on your computation machine. After I did a design on a 60V process I was so spoiled.

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Regards, Joerg

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Reply to
Joerg

HV ASIC processes are not cost-effective. You're better off using a low voltage process plus discretes... unless you're the government and only size matters ;-)

It's probably been close to 20 years since I last used a 30V process (not counting specialty processes with HV open drain or collector devices... like the DMOS processes now available).

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

The inductance spec seems to jump around from ~1mH to 10mH... maybe you have an ampere-turn spec... maybe ?:-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

This was 1997/98: 60V Delco process, grand total with masks, first silicon, my flights, but without my engineering time somewhere around $120k. However, I realize that NRE has gone up quite a bit since then.

When we fired it up for the first time lo and behold it worked. A major pool party over here was called for and held, booze and food provided by yours truly.

Man, I wish I could get such a deal just one more time :-)

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Regards, Joerg

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Reply to
Joerg

Where did the 1mH come from? Maybe I am getting old ...

It's likely a tad over 10mH. How large this "tad" is remains to be seen since the mechanics of the relays structure still need to be designed. Again, this is outside my influence, although we could fudge with the # of turns versus wire diameter a bit. But not to worry, I'll get it done. Was just hoping there'd be a solution in a can maybe from the world of diesel rail injection or whatever.

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Regards, Joerg

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Reply to
Joerg

You spoke of 1 Ohm and "ramping" to 3A, in a small fraction of a msec. Suppose that "small fraction" was 100usec, 24V implies 800uH.

Certainly exhibiting Alzheimer-style symptoms ;-)

If it's a "relay" why the speedy "ramping" requirement? It's going to bounce for some time anyway.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

Richard Davis?

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

Doesn't ring a bell but it's over 10 years now.

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Regards, Joerg

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Reply to
Joerg

spoiled.

Last I heard he was running the ASIC group at DELCO. He was one of my young bucks when I was at Motorola ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

Not this small of a fraction but even that would not be completely impossible. If someone says "impossible" that really gets my productivity up :-)

Think outside the box, that's what the world is paying us for. As I said in another post there are ways to goose a coil. For example with a very zippy boost converter, meaning one that really steps on it the microsecond the light turns green. It would not be my first one. My latest one was so tiny that I forgot it was there for a minute since it all was connected to an innocent 12V bench supply. It promptly bit me.

Ahem. Grumble. Don't joke about this stuff, several such cases to take care of in the neighborhood :-(

Not this one :-)

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Regards, Joerg

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Reply to
Joerg

spoiled.

Ok, then I probably do not know him. We did not use their design folks, just the foundry.

Old buck sometimes must see that young buck also make good stuff :-)

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Regards, Joerg

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Reply to
Joerg

national list LM1949N as obsolete, LM1949M as full production ...

-Lasse

Reply to
langwadt

Of course, I'm an excellent teacher ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

Microsecond? Show me ;-) "Goose" is what my "Nagle-solution" does.

"Use it or lose it" seems to fit quite well, at least in my observations.

Moving target. Tiring. Time for the vino ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    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
Reply to
Jim Thompson

Memory issues setting in? SCNR, but I did mention 120usec before in this here thread. When you step on the accelerator of a car it won't be at

60mph in a microecond either :-)

Anyhow, not at liberty to share that converter but I sent you another, a regular run-of-the-mills buck being ready at around 70usec. Not bad, eh? You have mail.

Not always. I knew folks who were very smart engineers and then ...

I design a lot for moving targets. Very normal business.

Just came out of the pool. Time for the cerveza.

--
Regards, Joerg

http://www.analogconsultants.com/

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Reply to
Joerg

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