Are TS555's really supposed to suck this much?
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From: Jim Thompson on 22 Jan 2010 17:52 On Sat, 23 Jan 2010 00:41:05 +0200, "Gerhard" <gvdberg(a)risccsir.co.za> wrote: [snip] > >I consider my self lucky to have experienced the days of BIG IC mask >drawings >and peeling Rubylift. > >Enjoy the weekend > >Gerhard van den Berg >CSIR > Yep. I used to do my own layouts and cut and peel the Rubylith myself. Maybe a hundred transistors maximum. Now my chip designs number in the tens of thousands of transistors ;-) ...Jim Thompson -- | James E.Thompson, CTO | 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.
From: Tim Williams on 22 Jan 2010 18:23 "bob monsen" <bmonsen(a)cisco.com> wrote in message news:1264197578.875722(a)sj-nntpcache-3.cisco.com... > Tim appears to be trying to do something that is not spec'd for the > device. He should use the discharge pin to power the LED rather than > trying to use the output if also using the output as a timing element. Duh! Thanks ;-) Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
From: Bill Sloman on 22 Jan 2010 18:49 On Jan 22, 11:41 pm, "Gerhard" <gvdb...(a)risccsir.co.za> wrote: > "Bill Sloman" <bill.slo...(a)ieee.org> wrote in message > > news:6f8f419d-feee-4396-aab4-4d3d26e0d253(a)22g2000yqr.googlegroups.com... > On Jan 22, 2:26 am, Archimedes' Lever <OneBigLe...(a)InfiniteSeries.Org> > wrote: > > > On Thu, 21 Jan 2010 16:15:53 -0800 (PST),Bill Sloman > > > <bill.slo...(a)ieee.org> wrote: > > >On Jan 21, 7:09 pm, John Fields <jfie...(a)austininstruments.com> wrote: > > >> On Wed, 20 Jan 2010 21:18:43 -0800, John Larkin > > Snip . . . . > > > >It's more that John Larkin is good at electronic design, and has > > >recognised precisely how useful the 555 is - which is to say, not a > > >useful device in most applications. > > > Why then is it STILL one of the most widely used chips in existence? > >Legacy design. It worked for specifc applications, back in 1971 when > > Hans Camenzind designed it, and people have been copying these > > circuits ever since. Not because there isn't a better alternative - > > there almost always is - but because finding out what the better > > alternative is, qualifying the new component and explaining to the > > boss why you've wasted your time solving a non-problem all take time, > > and while the time is usually well-spent, in the long term, lots of > > people have more immediate short-term concerns. > > Snip some more .... > > Hans R Camenzind has some interesting information on IC design > for those that would like to try their hand at it. > Search for the article "Redesigning the old 555" by Hans Camenzind. > It was published in the IEEE Spectrum Volume 34 Issue 9, Sept. 1997. > IEEE Explore has a copy of the article.http://ieeexplore.ieee.org/iel3/6/13487/00619384.pdf?arnumber=619384 The article seems to have gotten itself into Hans Camenzind's 2004 book "Designing Analog Chips" ISBN 978-1-58939-718-7 > I consider my self lucky to have experienced the days of BIG IC mask > drawings and peeling Rubylift. I saw his in action back in my first industrial job at Plessey Pacific in Melbourne around 1970. My colleagues used to cut Rubylith and ship it off to Plessey Researh at Swindon in England to be converted into silicon. A couple of weeks later, back would come a working analogue integrated circuit. Impressive. I can remember them being deeply envious of Bob Widlar's super-beta transistors, as used in the LM108. -- Bill Sloman, Nijmegen
From: John Larkin on 22 Jan 2010 19:35 On Sat, 23 Jan 2010 00:41:05 +0200, "Gerhard" <gvdberg(a)risccsir.co.za> wrote: >"Bill Sloman" <bill.sloman(a)ieee.org> wrote in message >news:6f8f419d-feee-4396-aab4-4d3d26e0d253(a)22g2000yqr.googlegroups.com... >On Jan 22, 2:26 am, Archimedes' Lever <OneBigLe...(a)InfiniteSeries.Org> >wrote: >> On Thu, 21 Jan 2010 16:15:53 -0800 (PST), Bill Sloman >> >> <bill.slo...(a)ieee.org> wrote: >> >On Jan 21, 7:09 pm, John Fields <jfie...(a)austininstruments.com> wrote: >> >> On Wed, 20 Jan 2010 21:18:43 -0800, John Larkin > >Snip . . . . > >> >It's more that John Larkin is good at electronic design, and has >> >recognised precisely how useful the 555 is - which is to say, not a >> >useful device in most applications. >> >> Why then is it STILL one of the most widely used chips in existence? > >>Legacy design. It worked for specifc applications, back in 1971 when >> Hans Camenzind designed it, and people have been copying these >> circuits ever since. Not because there isn't a better alternative - >> there almost always is - but because finding out what the better >> alternative is, qualifying the new component and explaining to the >> boss why you've wasted your time solving a non-problem all take time, >> and while the time is usually well-spent, in the long term, lots of >> people have more immediate short-term concerns. > >Snip some more .... > >Hans R Camenzind has some interesting information on IC design >for those that would like to try their hand at it. >Search for the article "Redesigning the old 555" by Hans Camenzind. >It was published in the IEEE Spectrum Volume 34 Issue 9, Sept. 1997. >IEEE Explore has a copy of the article. >http://ieeexplore.ieee.org/iel3/6/13487/00619384.pdf?arnumber=619384 >Google might have a link to a free copy of the IEEE Spectrum article. > >A short article on Hans Camenzind and the 555 design history is available at >http://www.eetimes.com/special/special_issues/millennium/milestones/camenzind.html > >The text and audio recordings of an interview with Hans on the design of the >555 and PLLs are available at >http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Index.htm >It covers most of the info in the IEEE Spectrum article. >There are however more detail and diagrams on the 555 design in the IEEE >article. > >I consider my self lucky to have experienced the days of BIG IC mask >drawings >and peeling Rubylift. > >Enjoy the weekend > >Gerhard van den Berg >CSIR > I read somewhere that the rubylith IC layout guys decided that 1 mil = 25 microns, to simplify their lives. I used to make pcb power and ground planes by cutting rubylith, with x-actos for the straight stuff and dividers to score circles. I am not the slightest bit nostalgic about hand-taping PC boards; it was a huge pain. Does anybody remember Lorry Ray? John
From: RST Engineering on 23 Jan 2010 13:33
On Fri, 22 Jan 2010 15:52:45 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote: >Yep. I used to do my own layouts and cut and peel the Rubylith >myself. > >Maybe a hundred transistors maximum. Now my chip designs number in >the tens of thousands of transistors ;-) > One of my college jobs was as a pcb layout artist. I got pretty good at it, if I do say so myself. First job out of college was an RF lab where (believe it or not) they forced us to use rubylith at 60 MHz. instead of black tape and donuts. Took me at LEAST 10 times longer to do the layout and nowhere NEAR as neat as with the regular stuff. I didn't stick around too long at that place. Jim |