You are here

IC design - how do they do that?

Customising, building or repairing your own gear? Need help with acoustic treatment or soundproofing? Ask away…

IC design - how do they do that?

Postby BJG145 » Thu Jun 21, 2012 6:06 pm

I was just looking at the picture of the innards of the CLASP system reviewed in May's SOS with its rows of chips, and it just baffled me. How the heck did someone create that? Could anyone give me an insight into the development process of something like this, or point me to a book or something? I imagine that something like this necessitates a team of specialists, but I don't know what the specialisms are. I mean, are there people who understand what a wide range of ICs do, without understanding how they operate, for instance...? A bit like knowing how to use an application without knowing how to write the code...?
User avatar
BJG145
Frequent Poster
Posts: 2986
Joined: Fri Aug 05, 2005 11:00 pm
Location: Norwich UK

 


Re: IC design - how do they do that?

Postby dmills » Thu Jun 21, 2012 7:23 pm

The person you describe is called an Electronics engineer, there may also be a software guy (But not always, plenty of electronics types can program micro controllers), and maybe a hardware cad person.

Something like CLASP decodes into really 24 near identical sets of routing electronics, a control processor, the PC plugins and some twiddly (but important) bits around the edges (Power supplies, control interfaces and such), as such it does not really appear all that complex to me, far worse is something like a big analogue synth where you have many different circuits instead of 24 sets of the same with some extra bits around the sides.

The biggest pain would have been either the PC software side or the sheer number of connectors in play, electronically the thing is not that complex (Bit like a mixing desk, lots of repeats of the same thing).

Analogue electronics usually needs the designer to understand at least a little about what goes on in the chips (Ebbers Moll and friends as a minimum), but silicon layout is a whole other (and highly specialist) game.

Interestingly modern digital design makes heavy use of hardware that can be configured by software, things called FPGAs, very cool technology and you can get tens of thousands of logic elements on a chip that you then configure into whatever circuit you want by writing a description in a hardware design language. This has largely removed the need to design custom digital chips at least for small to medium market products.

Regards, Dan.
dmills
Frequent Poster
Posts: 1543
Joined: Thu Aug 24, 2006 11:00 pm
Location: High Wycombe, UK

Audiophiles use phono leads because they are unbalanced people!


Re: IC design - how do they do that?

Postby hollowsun » Thu Jun 21, 2012 8:13 pm

BJG145 wrote:I mean, are there people who understand what a wide range of ICs do, without understanding how they operate, for instance...?
Yes. And there are people who actually design these ICs, not just piddly little things with a few pins on them but things with a millions of switches inside and billions of permutations.

I know a chap who can visualise such things in his head, mock it up using an FPGA (as dmills mentioned above) and then have it all cast in silicon!! That will then go into a product that he hasn't the first idea how to operate except at the most rudimentary level for testing! Other engineers working on the stuff will be at the top of the tree in their knowledge of audio, analogue and digital audio and electronics wit years, even decades, working on design and manufacture but will often (even typically) have no experience of actually using it.

I was at the aforementioned chap's house once - he was designing the ASIC (Application Specific Integrated Circuits - the really big bugger ICs at the heart of some gear) and the doorbell went so off he went to answer it. Came back : "Sorry - washing machine repair man"

"What? You need a washing machine repair man? Brain the size of a planet, building an ASIC with several million switches in it and you can't fix your own washing machine?!"

"Fix it? I don't even know how to use it!"

He's not the only electronics genius I've known who has trouble with an electric kettle!
User avatar
hollowsun
Frequent Poster
Posts: 2122
Joined: Thu Jan 20, 2005 12:00 am

Re: IC design - how do they do that?

Postby Hugh Robjohns » Thu Jun 21, 2012 11:30 pm

BJG145 wrote:I was just looking at the picture of the innards of the CLASP system reviewed in May's SOS with its rows of chips, and it just baffled me. How the heck did someone create that? Could anyone give me an insight into the development process of something like this

A lot of the 'chips' you see in that picture are actually sealed relays that perform the audio routing for the different operating modes.

However, from a design point of view it's really not all that complicated in concept. For a start, the analogue audio side is, as Dan says, 24 lots of some relatively simple signal routing performed via sealed relays between the I/O connectors on the rear panel.

The sealed relays themselves are controlled by some form of electronic switch which are commanded by the logic circuitry, part of which can be seen in the form of the two big chips on the base circuit board.

The logic circuitry and the relays need power, so there is a power supply in the box, with transformer, AC to DC rectifiers, smoothing capacitors, voltage regulators and all that.

Ther is also some logic and interfacing associate with the tape machine's remote transport control, and some front panel stuff to accept control commands from the panel buttons and to drive the panel displays.

Then there is the more complex, but relatively common data interface gubbins to communicate with the host computer, so that commands and tallys can be sent back and forth between the Clasp hardware and the computer... and then the computer software that generates the control plug-ins and interacts with the host DAW.

In effect, we are talking about a lot of separate functional blocks, each with specific design requirements, and input and output signals that must conform to specific design definitions and functions. To some extent, each can be designed with some independence of the others provided each meets its design requirements, and then the whole lot can be moulded together to form an integrated system that does what it is supposed to do.

Electronics engineering involves knowing how to design a power supply, logic circuits, audio and data buffering, microprocessor or microcontroller systems, and so on. There are specialists in different fields, of course, too. And then there are software engineers who can write plug-ins, DAWs, operating systems and so on. And sometimes the electronic engineers can do some of those things too... and vice versa.

Education is a wonderful thing!

A good place to start to get a handle on electronics design is a book called The Art Of Electronics I started with that book nearly 40 years ago!

hugh
User avatar
Hugh Robjohns
Moderator
Posts: 16947
Joined: Thu Jul 24, 2003 11:00 pm
Location: Worcestershire, UK

Technical Editor, Sound On Sound


Re: IC design - how do they do that?

Postby grab » Fri Jun 22, 2012 12:24 pm

Hugh Robjohns wrote:A good place to start to get a handle on electronics design is a book called The Art Of Electronics I started with that book nearly 40 years ago!

And it's still pretty much the bible today.

Like any complex job, the answer is quite simply that you keep breaking it down until you get to manageable tasks. You look at a cathedral and think "how the hell did they build that?!" And the answer, like any building, is one brick at a time. Just more bricks than usual, and a more complicated architecture job! But you do have to start from an initial idea of "it's going to work like *this*", and that's the real added-value part. It's why architects and civil engineers earn more than bricklayers.
grab
Frequent Poster
Posts: 2366
Joined: Sat Jul 07, 2007 11:00 pm
Location: Cambridge, UK

 


Re: IC design - how do they do that?

Postby James Perrett » Fri Jun 22, 2012 2:11 pm

Hugh Robjohns wrote:
A good place to start to get a handle on electronics design is a book called The Art Of Electronics I started with that book nearly 40 years ago!

One of my first jobs as a young electronics tech (around 30 years ago) was to incorporate one of Winfield Hill's cassette logger designs into a measurement system that we had designed. It was a very ingenious use of a stepper motor and very reliable.

I must admit that I don't have a copy of the book - but I had a very knowledgeable college lecturer who made sure that we had good notes which gave me a good start. I still have those notes around today.

James.
James Perrett
Moderator
Posts: 5816
Joined: Sun Sep 09, 2001 11:00 pm
Location: The wilds of Hampshire

JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.co.uk



Who is online

Users browsing this forum: No registered users and 1 guest