Author Topic: Which CAD/EDA tool to "invest" on ?  (Read 8019 times)

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Offline IamSynthetiCTopic starter

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Which CAD/EDA tool to "invest" on ?
« on: October 18, 2020, 11:32:38 pm »
Greetings everyone,
I am a student of Electrical Engineering & Computer Engineering, and i have been a fan of the subject for some time, designing and building my own things. I mainly use EasyEDA, as it is free, easy to use and learn. But now, as my projects grow more complex, and my needs are more demanding, EasyEDA fails me all the time.

So, I decided it is time to "invest" (time) on a proper CAD/EDA tool that would be widely used and recognised. I Started from the top, I found a Cracked versions of Altium (cant spend 3000 on software), and got thrusted into a huge complicated mess that i understood nothing about.

I am looking mainly for a tool that allows me to draw a shematic, simulate it, and ofcourse to work a PCB. But I am lost in a wirldwind of pompous marketing and outdated info, so i decided to come to the experts.

What do you think ? Is there an All-In-One solution (OrCAD,Allegro ???), What software should someone learn today, and ofcourse, what software do you use ?


Thanks in advance.
 

Online nctnico

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #1 on: October 19, 2020, 09:05:29 am »
Altium is pretty standard in small companies where Orcad / Allegro is standard in larger companies. Eagle seems to be pretty dead after it was taken over and turned into a subscribtion model together with the rise of Kicad.

If you download the schematics and boards files for evaluation kits for higher end parts you'll see the files are often made using Orcad / Allegro because it performs better for large designs. I can use my nearly 10 year old core-i3 laptop for complex 10 layers boards without any problem.

But be prepared to go through a long steep learning curve. I switched to Allegro not so long ago and spend a good 200 to 300 hours to master it to a level where I can create reasonably complex designs. Still there is lots of other functionality in there (like scripting) I have not touched yet.
« Last Edit: October 19, 2020, 09:07:14 am by nctnico »
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Offline AndyC_772

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #2 on: October 19, 2020, 09:11:36 am »
I use OrCAD PCB Designer, which is part of a closely related family of tools (basically different licence options) which includes Allegro.

Learning it will definitely not be time wasted, nor will it ever be a 'dead end' in terms of features and functionality.

The most basic tier is inexpensive, especially when it's on offer, which it was recently. Not sure what today's price is, but your local distributor should be able to let you know. Be sure to tell them you're a student - they may well be able to do you a better deal.

I've found that most of my clients either already use OrCAD themselves, or they didn't have any preferred CAD tool at all and were happy to accept my recommendation. It's certainly not been a 'wrong' choice in any sense.

Offline chris_leyson

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #3 on: October 19, 2020, 09:54:26 am »
Altium or Orcad/Allegro would be a good investment but either package will involve a steep leaning curve. I've worked for two or three companies in the UK that use Zuken.
 

Offline boz

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #4 on: October 20, 2020, 12:20:17 am »
"easyeda fails you all the time". You must really be doing some complicated stuff what kind of designs are you making ?
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Offline Pitrsek

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #5 on: October 20, 2020, 01:09:36 am »
Free student licenses are available for Altium
Plenty of resources on the web/youtube - both official and unofficial.
Imho the "huge complicated mess" is one of the better and more user friendly programs in the industry. You can do much,much worse (Yes, I'm looking at you Mentor...). Every ECAD program sucks in one way or another. Some more, some less...
Weather Altium or Orcad, depends probably more on your geographical area and industry.
 

Offline IamSynthetiCTopic starter

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #6 on: October 20, 2020, 08:09:08 am »
I see Altium and OrCAD are the most popular. I've been using Altium for about a week now and i am starting to get the idea. I think when i find some time, i will get a trial of each Altium and OrCad, and try to remake a project i made with EasyEDA, on each platform and compare. I will also ask at my university to see what the can offer.

Regardless, i still don't know how the prices go.I'm afraid i'll request an offer and get startruck by a 5K+ sum. What is a normal price for such a product ? And how, or where, can i find better offers ?

"easyeda fails you all the time". You must really be doing some complicated stuff what kind of designs are you making ?
I might have been a tad bit overdramatic in my statement, but it's no secret EasyEDA has so many problems and quirks that make your life hell. I mainly design high density analog,RF,High Speed and Digital boards (Sensors,microcontrollers,RF,W(siniFi and bluetooth). EasyEDA doesnt do very well, it slows, it'self and me, down to almost a halt.
 

Offline AndyC_772

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #7 on: October 20, 2020, 08:22:18 am »
Regardless, i still don't know how the prices go.I'm afraid i'll request an offer and get startruck by a 5K+ sum. What is a normal price for such a product ? And how, or where, can i find better offers ?

https://www.eevblog.com/forum/eda/orcad-price-drop/msg3225068/#msg3225068

Requesting a quote is free - get on with it!

Offline Feynman

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #8 on: October 20, 2020, 07:17:23 pm »
Regarding career opportunities I guess that having Altium in your tool box is a good idea. This depends a little on region and market, of course. I don't know about market share figures (does someone?), but if there is a "standard" too, I guess it's Altium. In our company we're using Pulsonix, but that's not a very wide spread tool (many even never heard of it). It's a good tool and there are some big companies using it. But I would stick to your plan and invest in a more standard tool.

I guess the global market is dominated by tools from the following vendors: Mentor, Cadence, Zuken and Altium.
Mentor has PADS (mid-range) and Xpedition (high-end), Cadence has OrCAD and Allegro, Zuken has CR-5000 and CR-8000 and Altium has the Altium Designer.
 

Offline Siwastaja

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #9 on: October 23, 2020, 08:32:33 am »
Any of the Big Names listed is not easier than Altium - they all require significant learning process - so if you are struggling with understanding Altium but have already put some effort in it, I recommend you give it another chance.
 

Online nctnico

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #10 on: October 23, 2020, 07:41:27 pm »
Any of the Big Names listed is not easier than Altium - they all require significant learning process - so if you are struggling with understanding Altium but have already put some effort in it, I recommend you give it another chance.
Still I have to say that for me Altium has been the least intuitive CAD tool I have used so far. I really needed to have the user manual on my lap to get the first (and last) projects done which where relatively simple (no matched impedance etc). Last year I had to start using Orcad Allegro from scratch and watching some videos and looking on a forum for some specific topics was enough to get going for a complex SoC design.
« Last Edit: October 23, 2020, 07:49:42 pm by nctnico »
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Offline Pitrsek

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #11 on: October 24, 2020, 06:22:02 pm »
I'd say it pretty much depends on which what package you start, to a certain point i believe it defines how you expect CAD package to behave. So for me Altium is the "intuitive one".
Mentor stuff, on the other hand...
 

Offline Doctorandus_P

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #12 on: October 26, 2020, 01:38:51 pm »
Several years ago I switched from Windoze to Linux, and also had need for a better EDA tool, as the tool I used then was getting quite old.

Back then I settled on KiCad. Partly just because I like Open Source applications, and rather donate to those, then pay up front for commercial applications withhout even knowing if it works well or how buggy it is.

For some reason EDA applications seem to have more bugs than other kinds of applications. Even expensive programs such as Altium apparently have long standing bugs and weird workarounds, and crash often on some computers.

KiCad has been growing in popularity quite a lot over the last few years. DigiKey has made some tutorials and Libraries for KiCad, several PCB manufacturers have specific guidelines for setting the net class rules in KiCad. For example: https://docs.oshpark.com/design-tools/kicad/

But to give better advice, tell us more about the limitations of the current program you're struggling with.
Is it some artificial limitation on pin count or board size or layer count?

KiCad also has some limitations in this regard. Board size is limited by 32 bit variables and 1nm resolution, which results in max PCB size of about 4 by 4 meters, and current limit on copper layers is 32. Limit on board pin count and board complexity is mostly irrelevant, and are mostly defined by the Hardware of your PC and your patience, but KiCad runs quite well on 10+ year old hardware.

You can find some links to existing designs on https://kicad-pcb.org/made-with-kicad/ to get an idea how KiCad performs on your hardware. The Olinuxino A64 design runs quite well on my current PC, (which is around 8 years old)

Simulation with ngSpice is built into KiCad, but it is in a bit premature state. One of the biggest problems is to find spice models that are not encrypted or rely on some vendor specific feature. I've done some simple simulations myself, and got them working, but my interest in spice is not very big. I mainly do uC related digital circuits myself.
 

Offline SiliconWizard

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #13 on: October 29, 2020, 05:40:41 pm »
Probably already all said. The obvious: it actually... depends.
Not all tools fit all needs. And given money is usually a parameter, investing in something expensive if you're only using 10% of its features is just wasted money.

Beyond your needs in terms of features and the cost, then there is the context. The choice of an EDA tool will also largely depend on the context. Is it for student use? Is it for personal/hobbyist use? Is it for a company? (in which case, unless this is a very small company or you're head of engineering, there is little chance you'll get to have a word anyway.)

KiCad has now indeed progressed enough that it can be decently used in many kinds of contexts. But, in medium/large companies, it will still be much more common to see a commercial EDA.

If your question implies the underlying question: "what EDA should I learn in order to improve my employability", then of course this is yet a different point. And still, there wouldn't be a single answer. It would all depend on the kind of company you're interested in working at, and the kind of job. Some companies will not care - as long as you have any previous basic knowledge of any EDA, it will be OK, unless you're specifically applying for a position in which layout will be your main task. Which leads me to a corollary: specific EDA knowledge most often matters more for the layout part than anything else. Nobody will really care if you know how to draw a schematic using the schematic editor of some EDA. It's usually pretty straightforward for anyone with basic knowledge after a few minutes of use. If the EDA embeds some kind of sophisticated database, that could be some useful knowledge too, but that's about it IMHO.

In any case, there are many EDA tools out there, so focusing on just one, if you want to improve your employability, is not necessarily a smart move, or at least useful. All I know is that Altium is pretty popular, and seems excessively so in Australia, for instance. So if you're going to work in Australia and have to make a choice, learning Altium would probably make sense. In other parts of the world, you'll see more of Orcad, or Mentor, or Cadstar, or...

And frankly, if you're thinking of investing your OWN money as a student, I would just suggest keeping your money for more useful stuff and use KiCad. Now if you get access to one of the major EDA through your university for free, then fine.
 

Offline Shadowfire

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #14 on: December 08, 2020, 03:09:45 pm »
I'm going to ride on the coattails of this thread instead of starting a new one.

Recently both Cadence and Altium has put out special offers on Altium Designer and Orcad professional for $4000 for a license.

BACKGROUND:  I currently work for a mid-sized company which has a very small (3-person) controls team and we (and by "we", I mean "I") are using Orcad PCB Designer professional with PSPICE (with CIS) to generate boards for our in-house custom testing fixtures.  I run spice simulation on the analog portions of the board, and SI simulation on any digital receiver net on the board.  I've previously worked at a contract manufacturing plant where we had access to both Orcad and PADS.

I have personal, existing licenses of Circuit Studio (which doesn't even have primitive SI and sits unused because of this) and Orcad Standard (which at least allows pre-route SI tests, which if I'm careful with setup can get to "close enough" to the final board, since I am primarily concerned with signal overshoot and not ISSI as I have no gigabit signals on anything I do at home).

1.  Analog simulation will be a must for associated analog circuits.  Information about Orcad on Cadence's web site is close to nonexistent.  They seem to have abandoned it to their distributors (in NA, which is EMA-EDA).  Based on the information that I can pull up, it looks like PSPICE isn't a part of PCB Designer professional, rather an addon purchase.  This is sort of a black eye on Orcad, since I will have to run simulations in LTSpice, and I won't be able to use Orcad Test Benches or Pspice to run simulations. 
2.  I will also require "low speed" signal integrity, as I am doing a bunch of digital designs, so SI simulation with support for IBIS models is a must.  I also plan on eventually adding DDR3/DDR4 memory systems, and need to be able to simulate SI for that.   Orcad has a wonderful tool for this with their Sigrity SI, a basic version of which is now integrated with Orcad professional, which shows impedance as colors across your board, visually showing where traces might cross split planes, be too close to copper fills, or run through vias which cause a significant Z0 change, as well as Signal explorer's post route simulations (which also is a stripped down version of the full package, but is certainly good enough for low speed signals that I use at work).  How does this compare with Altium's build in SI simulations?
3. Altium seems to also include PDN and thermal simulations.  Any comments about how useful these really are?  Do you actually use them, or do you use a 3rd party tool to do the job (and if so, why)?

Thanks in advance.

 

Offline olkipukki

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #15 on: December 08, 2020, 06:42:43 pm »
Thoughta basic PSPICE is part of Pro edition, but you need more - they offer extra $$$ editions.
 

Offline mstevens

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #16 on: December 08, 2020, 09:46:27 pm »
A version of PSpice is included with all versions of Orcad. Including Orcad Standards see the page... https://www.ema-eda.com/offers/purchase-orcad-today?_bk=buy%20OrCAD&_bt=&_bm=e&_bn=o&_bg=1280931392171763&msclkid=7a3c4e460dec1319c3d61189fefc8fc6
 

Offline Shadowfire

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #17 on: December 08, 2020, 10:35:28 pm »
That seems to be the Lite version, which is limited to 75 nodes, 20 transistors, no parameterized parts, only imports models with 2 pins, etc.
Basically unusable for anything more complicated than "Hello world".  I already have this on my Orcad Standard edition, forgot about it, and remembered why I wasn't using it.
« Last Edit: December 08, 2020, 10:41:11 pm by Shadowfire »
 
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Offline ElectronRob

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #18 on: December 10, 2020, 02:13:53 pm »
It depends what your doing really.

Just to learn? And later evolve into charging for work....?

I would start out free, Kicad/designspark and later move onto something 'more proper'.

I started out with Protel99se, which frankly did everything 90% of 'designers' could ever need, I later moved onto Orcad, and then again Orcad/Allegro and for the past 5 years have only used Altium. For learning Altium is great, simple, powerful etc. I found Orcad/Allegro to be a real chore to use but would mention that Allegro its self is very flexible. 

Another option would be to Circuit Studio, its a simplified version of Altium, its very user friendly and would let you do most things, later when you have some money behind you jump to Altium safe in the knowledge that all your CS designs can be easily imported and used.

 

Offline ElectronRob

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #19 on: December 10, 2020, 02:30:57 pm »
Do you absolutely need SI? I find the chore of setting it up vs. using experience and simulating modules externally in LTspice/TINA to be pretty effective. Best of all is a real life prototype to hack about. I am not alone in the opinion that simulation is only as good as the person driving it, and often if you are good enough to drive it you are good enough to not use it for most analog/low speed stuff..... Not a criticism, just a question. I know of designers who insist on simulating EVERYTHING and truly believe that the simulation represent reality 100% more often than not it is their designs that do not work. 

Also as a heads up. Altium does not include PDN or thermal as standard, its a cost plus option (emphasis on the large plus), their videos are pretty awful and have done nothing to encourage me to add it. Altium obviously does length match together with impedance fairly well the simulation looks ok but I really don't use it much as I prefer external tools however most of my work is either very high current switchmode or very low noise instrumentation both of which in my experience tend to not simulate well due to the influence of non real components, PS most of my work is also sub 10Mhz so I can see the advantages of good simulation for something like a high speed memory interface - although even then length matching and simple impedance control/sensible layout has done me well on that limited front so far.

You can get a 1month free trial of Altium which I would suggest you do. Learning curve is low if you already know the design flow from something such as Orcad. Strong user base means you will have answers to questions (simple and complex) pretty quickly.

Good luck
 

Offline asmi

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #20 on: December 10, 2020, 03:34:00 pm »
Do you absolutely need SI?
Everyone absolutely needы SI. Some people just hasn't realized that yet :)

Also as a heads up. Altium does not include PDN or thermal as standard, its a cost plus option (emphasis on the large plus), their videos are pretty awful and have done nothing to encourage me to add it. Altium obviously does length match together with impedance fairly well the simulation looks ok but I really don't use it much as I prefer external tools however most of my work is either very high current switchmode or very low noise instrumentation both of which in my experience tend to not simulate well due to the influence of non real components, PS most of my work is also sub 10Mhz so I can see the advantages of good simulation for something like a high speed memory interface - although even then length matching and simple impedance control/sensible layout has done me well on that limited front so far.
Sorry, but Altium's SI tools are useless junk and just don't work. Take a look at Orcad's impedance and crosstalk "visions" to see how it SHOULD BE done. The only people who say that simulation tools in Altium are good are those who never used them outside of demos/examples.
AD does have it's strengths, but sims is definitely not among them.
« Last Edit: December 10, 2020, 03:43:01 pm by asmi »
 

Offline asmi

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #21 on: December 10, 2020, 03:38:36 pm »
1.  Analog simulation will be a must for associated analog circuits.  Information about Orcad on Cadence's web site is close to nonexistent.  They seem to have abandoned it to their distributors (in NA, which is EMA-EDA).  Based on the information that I can pull up, it looks like PSPICE isn't a part of PCB Designer professional, rather an addon purchase.  This is sort of a black eye on Orcad, since I will have to run simulations in LTSpice, and I won't be able to use Orcad Test Benches or Pspice to run simulations. 
Yes, it's the paid addon, though my experience shows that Cadence reps are much more willing to negotiate on price/options that Altium ones. So ask them to throw in SPICE and see what they say.

2.  I will also require "low speed" signal integrity, as I am doing a bunch of digital designs, so SI simulation with support for IBIS models is a must.  I also plan on eventually adding DDR3/DDR4 memory systems, and need to be able to simulate SI for that.   Orcad has a wonderful tool for this with their Sigrity SI, a basic version of which is now integrated with Orcad professional, which shows impedance as colors across your board, visually showing where traces might cross split planes, be too close to copper fills, or run through vias which cause a significant Z0 change, as well as Signal explorer's post route simulations (which also is a stripped down version of the full package, but is certainly good enough for low speed signals that I use at work).  How does this compare with Altium's build in SI simulations?
See above - Altium built in SI tools are useless junk compared to what you have in Orcad Pro. The situation is so bad that I have to export completed PCBs from Altium into Orcad PCB Pro so that I can run SI sims to make sure the board will actually work.

3. Altium seems to also include PDN and thermal simulations.  Any comments about how useful these really are?  Do you actually use them, or do you use a 3rd party tool to do the job (and if so, why)?
This is a third-party paid addon which costs about $5k from what I heard. So maybe it's good, but for 5K? Thank you, but no thank you.
« Last Edit: December 10, 2020, 03:43:47 pm by asmi »
 

Offline olkipukki

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #22 on: December 10, 2020, 05:43:36 pm »
Yes, it's the paid addon, though my experience shows that Cadence reps are much more willing to negotiate on price/options that Altium ones. So ask them to throw in SPICE and see what they say.
Do you mean OrCAD PSpice Designer or something else?
 

Offline asmi

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #23 on: December 10, 2020, 06:31:34 pm »
Do you mean OrCAD PSpice Designer or something else?
Yea, that's what I think it's called. I work mostly in the digital world, so I don't really need PSpice beyond simple circuits like DC-DC converters for PDS, but for those who need it I can see the appeal.
Also, for those serious about high-speed designs, there is SI option for the Orcad Pro, which enables parametric sweeps in SigXplorer (for example it allows to find an optimal termination resistor value for a given physical topology by sweeping through a range of values). Without that option you can still do this manually by updating the value and re-running, so it's just a time-saver, but it might potentially save a lot of time if you do a lot of designs with DDRx buses (which often require parallel termination for address/control lines).
Also, recently TI released free PSpice simulation tool which, as understand it, is essentially a cut-down and locked-down version of Orcad Capture PSpice tool. I didn't try it myself yet, but it might be worth a shot for those who need it.

Offline ElectronRob

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #24 on: December 10, 2020, 06:57:59 pm »
Many people have done a great many things without SI, some quotes from Bob Pease come to mind. Note that did not say Altium simulation was good? I said I rarely use simulation features within Altium because I prefer to do any simulation using external software, mostly because I have used LTspice and TINA for quite a long time so its faster for me, I also explained why I don't tend to even need to do any simulation.  :-//

But each to their own, if you feel that you won't do a good job without simulating every last detail then kudos to you, what ever works is whats important, but I would suggest there is a big difference between designing high speed digital circuits and analog. Cross talk is fairly straightforward to estimate, so I haven't found it an issue so far to work out what the cross talk will be between two parallel traces and to set design rules for a whole bus based on that. I did just look at the Allegro crosstalk vision and it looks really nice IF your design needs it, many don't.

I would agree that Altium is falling behind in this area, for example it really annoyed me that PDN is a cost plus option when AD is supposed to be their flagship product, also its not just expensive, you also need to pay maintenance on it, it basically costs the same as a whole new licence or AD which is mental, plus they do a really terrible job at selling it.

However, if you want a nice, easy to use bit of software with many good features Altium is still a solid choice, I find it easier to use than Orcad but that is perhaps because I spent so much time using 99se. My advice is still to get some demos and see which you get along with most.


 

Online nctnico

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #25 on: December 10, 2020, 09:59:22 pm »
Many people have done a great many things without SI, some quotes from Bob Pease come to mind.
However, Bob Pease never dealt with (for example) memories running at >1GHz where SI really matters. Being able to run a simulation of the signal integrity of a board can save thousands of euros/dollars on a board respin alone (without taking the costs of delayed sales into account).
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline olkipukki

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #26 on: December 10, 2020, 10:22:28 pm »
Also, for those serious about high-speed designs, there is SI option for the Orcad Pro
I'm a bit lost here, is it part of OrCAD Pro or a separate package?
 

Offline asmi

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #27 on: December 10, 2020, 10:45:59 pm »
I'm a bit lost here, is it part of OrCAD Pro or a separate package?
It's a feature of SigXplorer (which itself is a part of Orcad PCB software package), but it's only unlocked if you have SI license option.
With Orcad, all license levels are physically the same product. They simply disable/enable certain features/functions based on what license you have installed/activated. Which is one of it's strength in my opinion, as you can start small (baseline Standard or Pro level) and add extra options and features as you need them, while still using the same basic software - so no learning curve, and no software installation/configuration is required - you just add a new license, and additional features are unlocked.

This is a bit of offtopic, but I think Altium should've done the same thing to create cheaper "editions" of AD instead of essentially developing the same thing tow more times for Circuit Studio and <whatever their free cloud thingy is called>. That way transition to higher level would be much more painless than it is right now.
« Last Edit: December 10, 2020, 10:54:07 pm by asmi »
 

Offline olkipukki

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #28 on: December 10, 2020, 11:09:06 pm »
I'm a bit lost here, is it part of OrCAD Pro or a separate package?
It's a feature of SigXplorer (which itself is a part of Orcad PCB software package), but it's only unlocked if you have SI license option.


Are you sure about a separate license?

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Starting in 16.5 and continuing to the present version (16.6), you can perform signal integrity (SI) analysis from your OrCAD PCB board file using only your OrCAD PCB Professional license (no special SI licenses needed!)
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The SigXplorer tool which is using your OrCAD PCB Designer Professional license will open with a copy of your net’s topology.

https://resources.ema-eda.com/blog/how-to-perform-signal-integrity-analysis-on-nets-in-orcad-pcb-designer-professional
« Last Edit: December 10, 2020, 11:15:25 pm by olkipukki »
 

Offline asmi

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #29 on: December 11, 2020, 12:58:03 am »
Are you sure about a separate license?
SigXplorer is available at all license levels (even the most basic Standard), but it has some features disabled at lower levels. At standard level, as far as I remember, only pre-route simulations are available. At professional level (which is what I have BTW) you can do everything except parameter sweeps. That last feature requires SI license. They might've changed things in version 17.4, but I only have a license for version 17.2.
 
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Offline ElectronRob

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #30 on: December 11, 2020, 01:39:08 am »
And neither do I thankfully :)

You've also kindly made my point for me, high speed digital design is a great use of SI, using it for everything all the time is not.
 

Offline asmi

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #31 on: December 11, 2020, 02:51:36 am »
You've also kindly made my point for me, high speed digital design is a great use of SI, using it for everything all the time is not.
And you'd be wrong. Crosstalk can become an issue even in low-speed designs. The classic example is reset line which goes along some signal line with sharp edges, and in certain conditions enough of a signal can couple into reset line to trip the processor into reset. I've seen few boards which have this problem, and one of those was designed by no other than yours truly - that was back when I, just like you are now, thought that crosstalk is only a problem for high-speed lines. Well, I learnt that lesson the hard way :-BROKE If you don't want to repeat my mistake (with literally weeks of debugging and banging my head against the wall before I was able to figure out what the problem was), I'd recommend you to pay attention to this problem. This is especially so if you use modern low-power low-Vcc devices, as the lower the interface voltage, the lower the gap is between logic zero and one, and less of a crosstalk is required to trip the circuit. You can actually calculate crosstalk using free Saturn PCB Toolkit - play around with it, and you will see it doesn't take that much to cause problems, as modern chips have very sharp edges, even cheap STM32F4 MCUs can output signals with rise time of only 2.5 ns, more advanced MCUs and pretty much all FPGAs can reach sub-nanosecond rise times.
Just for reference, at 3.3 V Vccio and typical 1.6 mm two layer FR4 PCB (Er=4.6), for 1 ns rise time signal it takes less than 10 mm of coupled length at 0.25 mm apart to have 3.2 V crosstalk spike in adjacent trace, for 2 ns the coupled length is 15 mm for the same spike, for 5 ns rise (which AFAIR even atmega328p can reach) you need about 40 mm of coupled length. As you can see, it doesn't take all that much to cause issues which are going to be *extremely* hard to debug because presence of debug probe and even your hand will change the behavior (because it will change load capacitance of the trace).

Offline ElectronRob

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #32 on: December 11, 2020, 11:18:49 am »
Hi,

Thank you but I think we are drifting a little far from topic now. I understand what cross talk is, I understand what I like to use sim for. I am not a perfect designer (who is?) but I have been designing a variety of solutions for some 15 years now, even the worst designer would be familiar with cross talk by now :) I mostly design very low noise or very high current circuits, switching 1500amps through an Hbridge does indeed present some problems with control lines etc.

High speed digital IS a great application for SI - why am I wrong there. I already calculate crosstalk for anything important and guess what, I use Saturn PCB I did say thats what I did earlier.... you seem to think im disagreeing with you, I am not but I am also not asking to be educated here - but thank you for trying, I think you are being nice about it.

I am sorry to hear that you spent weeks of debugging, I would suggest you purchase some good test equipment and a good differential probe (or several!), I would also suggest that you slow any line down which doesn't need to be fast, do you really need that 2.5nS rise time to turn on that LED?

 :-+
 

Offline Shadowfire

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #33 on: December 28, 2020, 11:15:49 am »
I made the decision to go with Orcad PCB Designer Professional and added the Pspice option, instead of Altium Designer.

In the end the two packages seemed closely matched; it was primarily due to being the same package as I use at work, but there were a few other minor factors pushing me in that direction.  Keep in mind that I haven't actually used Altium (although I have used CircuitStudio), and that I've spent 5+ years using Orcad at work;  I'm going by the documentation that Altium had on their website.

1. XSPICE vs PSPICE:
PSpice seems to actually have component manufacturer support (models).  No need to go get an NDA with every component manufacturer to get an unencrypted model (which you will likely not get if you aren't working for a company).  Additionally the Pspice smoke option doesn't seem to have a counterpart in Altium.  (Yes you should be designing things with adequate safety margins... but changes happen, and isn't it better to not have to recheck everything manually because you made a minor change?  Smoke allows you to see problems with a cursory inspection.)

2. Signal integrity:
Both packages seem close to on par with IBIS models/signal simulation (The only significant difference I noted was that Orcad models the vias, but Altium does not.)

If Altium only generates text reports for SI, I can completely understand why asmi think that Altium is junk (although I think that the term "primitive" is probably more accurate).
The SI visual analysis tool (for impedance and crosstalk) in Orcad PCB Editor is **wildly** better than just having a text report with calculations & coordinates.

Basically, it seemed that wherever I looked and found an appreciable difference, Cadence's solution seemed more time-efficient.
« Last Edit: December 28, 2020, 11:17:36 am by Shadowfire »
 

Offline olkipukki

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #34 on: December 28, 2020, 05:33:44 pm »
I made the decision to go with Orcad PCB Designer Professional and added the Pspice option, instead of Altium Designer.
How much did you pay for the option if I may ask?
 

Offline Uky

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #35 on: February 06, 2021, 03:26:04 pm »
Things to consider when deciding what tool to "invest" in:

1. Are you considering a career as a professional PCB Designer?

The PCB designer community is getting older and many young are not that eager to pursue
careers in professional PCB design. This is IMHO partly because PCB designers are often considered
"draftsmen" with little or no esteem amongst design engineers.

Having one foot in the electronic design community and the other as a CAD engineer could prove
to be difficult. However - A skilled PCB engineer that masters a complex tool with good
knowledge in signal integrity issues as well as complex PCB systems will be saught after.

2. If an entrepreneur, do you forsee that your business will grow in terms of product
complexity? Choosing a tool that you can grow with means that the most important
part of the investment can be maintained: The libraries. Being (reasonably) experienced
with Cadence OrCAD/Allegro, it is possible to start with an inexpenceive version and
later purchase performance upgrades. The libraries will stay intact. No need for changes.

I guess that the more expenceive competitors provides this option as well.

3. Need for technical support? Is there any 24/7 support service if your design
crashes for whatever reason?

4. Any need to interact with other businesses that uses different systems?

I have seen questions such as "How to produce a net-list for a (competitors) PCB Editor".
Previously, OrCAD could produce a lot of netlist formats even for defunct
systems such as "EEDesigner" (DOS-based), but with 17.40 this option has been lost.
And it is of course understandable. What is important however is the possibility to
import other vendors schematics and PCB-files!

5. Are there possibilities to interact with mechanical tools?

Personally, I consider AutoCAD to be Cadence' "best friend" because of the flexibility to handle
arbitrary shapes of footprints and board outlines. Since 3D has become important, having
an interface to import and handle STEP-models are becoming more and more important.
Hence also knowledge of softwares such as Inventor/Solid works etc is an asset.

6. Are there possibilities to produce output formats such as IPC 2581 and ODB++?

There was a "fight" some years ago between Cadence advocating 2581 and Mentor, advocating ODB++ (which they owned
thanks to the purchase of Valor). (It seems that the dust has settled now)

If the answers to the questions above is no or not likely, I would definitly go with free software.
I am however watching KiCAD since I see this tool getting more and more competent
and gaining momentum.
The question is what happends if the driving forces looses the will for whatever reason.

This is a risk with any software but IMO, it is less likely for the big guns.
 

Offline Shadowfire

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Re: Which CAD/EDA tool to "invest" on ?
« Reply #36 on: February 20, 2021, 08:21:40 pm »
Just wanted to chime in that the Orcad PCB designer pro package has an astounding setup for PCB impedance and crosstalk analysis.  (It's apparently a cut down version of their Sigrity tool, but oh my god is this thing an amazing time saver.)

Lay out your board.
Do your initial routing.
Check your routing SI with the topology explorer and fix any reflection/routing or termination issues.
Use coupling (crosstalk) vision to space out your traces and minimize crosstalk.
Use impedance vision to find impedance discontinuities (vias on plane splits, adjacent vias, traces crossing over plane splits, traces running adjacent to copper pours, etc).  This will also show you if you missed any impedance constraints in constraint manager.
Final routing SI checks with topology explorer.
 
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