Clamping makes no sense for logic families designed to operate off a wide r ange of power supplies and able to withstand being mixed up with logic oper ating off different supplies. Your thinking is very 1970ish. Nothing wrong with the architecture, it is used in some extremely fast logic families, it has been perfected IOW. Finally, the modern gate oxide process does not bl ow a hole instantaneously when the voltage stress exceeds some threshold by one microvolt. It is a graded breakdown that requires time.
You seem to be mainly versed in yourself. Maybe JF will write a poem in your honor.
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John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
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Please do me the honor of keeping your mouth shut. I have no interest in your opinions.
I can confirm as fact an LT part that simulates nicely, but fails on the PCB, confounding the FAE, and, now, the factory.
NOLA white trash. ...Jim Thompson
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| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
I don't see much of a point in doing that. The switcher can deliver a certain amount of energy per cycle, mainly set per R5 and V2. So for long term sims you could just assume a current source that's curbed when the regulated output voltage is reached.
If you absolutely have to simulate with 4000uF you could set the inductor coupling to k=1 which helps a little, then play with abstol and reltol. But it'll still take forever. 4000uF is huge. Like modeling rear axle shock response for one complete Sahara desert crossing.
The last sentence sums it up what is missing: How many volts above abs max are allowed over how many milliseconds or microseconds? There use to be family specs and stuff like that but not anymore.
--
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
With all the cap load that I can stand to sim, it actually bursts. That is probably good in my application.
It does run at about 300 KHz, which isn't what I expected, given the timing resistor. Maybe, with the inductor I have, it's skipping clocks waiting for the current to build up to the peak trip point. OK, go ahead, force me to buy a smaller, cheaper inductor.
Mantis and Metcal next!
--
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
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There's no need to, since Jim's doing all right.
But Wow, that poetry thing really has you wired up, huh?
It's something that you're not good at, which casts aspersions on you,
and which you can't refute using your crude complaints.
Nice, hard-working, innocuous people, mostly. JT has bragged about what a vengeful, unforgiving lot the Thompsons are, himself included. Hey, I believe him.
He could actually provide some on-topic content once in a while. Like what part it is and what the problem is.
Hell, you could provide some on-topic content once in a while, instead of just whining about personalities.
--
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
Learn to read... your comprehension is REALLY BAD... "confounding the FAE, and, now, the factory" ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
Who really gives a f@#$ what Larkin opines? ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
And the jerk forced a 10ns max timestep... what did he expect?
Plus... apply Thompson's rule... any simulation which staggers along indicates a bad circuit design. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
That is because the comp node (Vc) initially rails. Once the converter reaches regulations and Vc comes off its peg it goes slightly above
1MHz, like the datasheet says.
Que quieres decir con eso?
I thought the Mantis is fixed, and the illumination ring gloweth again. I've always liked the tower-look of Metcals but they are just too durn expensive for my taste.
--
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
I'm not sure. The work was done in Auckland, NZ, by my client, not by me, I don't do PCB's, I only do chips... and my 64-channel LED driver is working gorgeously.
FAE == LT Field Application Engineer... he couldn't figure out the problem... it was built exactly to the data sheet. Problem sent off to the factory, who, 4 months later, still haven't resolved the issue.
I was asked to simulate it on LTspice, which I did, and the simulator says it works... actuality says it doesn't.
LTC3853, oscillates/loop-instability; running as 3-phase single-output. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
Adding a point... the part is peddled as a 3-output device, but the application note shows 3-phase single-output operation. I suspect this was just thrown onto the data sheet without physical testing, just simulation of a _behavioral_ model >:-} ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 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.
Those multiphase slope-compensated things are prone to all sorts of loop funnies, including sub-cycle oscillation. Cap ESR matters a lot.
Running at higher frequency sometimes helps.
Is the problem on an eval board, or a new design?
--
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
Well, Jeorg you could use two stage protection; say 50 ohms then a 5.6 V zener to ground, then another 100 ohms and a 5.1 or even 4.7 volt zener to ground. Either way, you have to decide.
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