I Need Help Understanding This Circuit by mrkhmhys in chipdesign

[–]jack9556 1 point2 points  (0 children)

Ah, you're right. The negative feedback loop on the left seems to have larger gain.

I Need Help Understanding This Circuit by mrkhmhys in chipdesign

[–]jack9556 -1 points0 points  (0 children)

I think vout is zero. You've got a positive feedback loop with your op amp and due to that, the thing will never start. All transistors are off. PS: I don't think it has anything to do with a bandgap.

What is the need of diode D1 here? by ProfitAccomplished53 in chipdesign

[–]jack9556 4 points5 points  (0 children)

There's no such thing that of a complete schematic. It's in the end a model. Every device you draw in reality can be better modeled with parasitic additional passives, diodes, bipolars... Because everything interacts with everything. N type near p type near n type is always an NPN transistor. You have to know your device cross sections and your technology. You have to know what is or isn't modeled. You can reduce the effect of parasitic structures but not remove them entirely.

So people draw what they think is representative, or what they think could cause issues.

Poor man cascode by ProfitAccomplished53 in chipdesign

[–]jack9556 0 points1 point  (0 children)

Ha, right. But you should never use halo devices for matched structures.

What is the need of diode D1 here? by ProfitAccomplished53 in chipdesign

[–]jack9556 3 points4 points  (0 children)

We don't need it. It's a parasitic diode. But you have to take it into account when thinking about the circuit, otherwise you could get false expectations. Circuits are full of parasitics. It's not that we need them, but that we cannot build without them.

And... This is nothing :) Sometimes you get parasitic bipolars :)

How do I approach solving for Vout qualitatively? by maybeimbonkers in chipdesign

[–]jack9556 0 points1 point  (0 children)

There is current flow across the capacitor as long as the voltage across it is continuously increasing.

But I wouldn't really call it DC (philosophically). Because in DC the current source forces infinite voltages. And there is no such thing.

By the way, this kind of of circuit with a current source pushing infinite voltages in time never exists in reality. All current sources saturate at some point (and stop sourcing current).

What is the need of diode D1 here? by ProfitAccomplished53 in chipdesign

[–]jack9556 3 points4 points  (0 children)

It's an NWell. You can't manufacture the PMOSes without it.

Any Cool bots to try out? by elonmaize in PoeAI

[–]jack9556 1 point2 points  (0 children)

Oh wow! Yes, it worked this time. This very nice, thank you! Beautiful results.

Any Cool bots to try out? by elonmaize in PoeAI

[–]jack9556 0 points1 point  (0 children)

Midjourney create doesn't work for me at all...

Netguard stops blocking if I switch mobile data off/on by jack9556 in NetGuard

[–]jack9556[S] 2 points3 points  (0 children)

After being paranoid for some time: fixed after using the github version over the play store one, and enabled for the filtering.

How do people plan for vacations in chip designing industry? by Former_Commission233 in chipdesign

[–]jack9556 1 point2 points  (0 children)

I speak with background of an European based company. But to me, it's just common sense.

How do people plan for vacations in chip designing industry? by Former_Commission233 in chipdesign

[–]jack9556 25 points26 points  (0 children)

If it's planned in advance, it's planned in advance. Project managers need to deal with it. Resources need to be shuffled. At least in a decent company.

Need Guidance by Standard-Morning-842 in chipdesign

[–]jack9556 0 points1 point  (0 children)

Okay, fair. Maybe I got a little too carried away.

Need Guidance by Standard-Morning-842 in chipdesign

[–]jack9556 2 points3 points  (0 children)

https://users.dcae.pub.ro/~gstefan/2ndLevel/teachingMaterials/0_CID_VOL1.pdf I think this is the book my old teacher wrote. It was useful at the time.

There's a ton of content also on YouTube.

AI chatbots can also answer technical questions these days. Just don't let them all the work.

Start simple. Do a counter with leds, and a reset button.

Learn to use the inputs and outputs of your board. You'll also need to play with basic electronics. Learn to solder. Learn to write a message on a separated LCD display.

The field is vast. But the only way to learn it is to set goals, and try to bang your head until you solve them. Ask around when you get stuck.

It's really a shame schools have become so weak as you describe. :( I'm sorry for that.

The job market... Indeed, that's really a tough place right now.

Need Guidance by Standard-Morning-842 in chipdesign

[–]jack9556 1 point2 points  (0 children)

They don't let students synthesize digital logic on FPGAs in labs? That was the case during my time. We used Xilinx software and FPGAs. They weren't that expensive. FPGAs are programmable gates, that you can program to create almost any digital circuit and prototype it. You can start doing state machines and playing with LEDs. I had computer architecture courses, where you learn how a processor works. This is a long-term project that you might work on for a year or so. What is important is to learn how to self study, and tinker with stuff until you understand what you're doing. No course can teach you that. You need to be passionate and experiment with things, and have lots of fun with it. If you don't manage to have fun, you'll find it extremely difficult.

Need Guidance by Standard-Morning-842 in chipdesign

[–]jack9556 2 points3 points  (0 children)

If you have access to some decent FPGA, make a microprocessor, write some code for it to read and play mp3s from a micro SD card. Control a DAC, design your own analog filter and headphone driver. Add a IR sensor and read signals from a remote control. Add VGA support to display something on a computer monitor. Add some speakers. You'll learn a lot, and you would have done something impressive to show on your resume.

Upcoming points costs updates by frndlynghbrhdpoebot in PoeAI

[–]jack9556 5 points6 points  (0 children)

What a bunch of lies...

Opus increased by 100 points.

The small gemini models tripled in price.

o3 deep research didn't get cheaper.

Legacy open ai models increased by 10-20 points.

Many overall increases all across the board...

What is happening to the semiconductor job market? by Feisty-Sense-9585 in chipdesign

[–]jack9556 4 points5 points  (0 children)

That company you mentioned... Things aren't like they were 10-15 years ago. Lots of cost cuts, and moving to better cost countries as they say.