some breadboards
in [Design]
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From: Nico Coesel on 9 Apr 2010 14:54 brent <bulegoge(a)columbus.rr.com> wrote: >On Apr 8, 8:57=A0pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Thu, 08 Apr 2010 19:46:29 -0500, "k...(a)att.bizzzzzzzzzzzz" >> >> >> >> <k...(a)att.bizzzzzzzzzzzz> wrote: >> >On Thu, 8 Apr 2010 17:12:33 -0700 (PDT), brent <buleg...(a)columbus.rr.com= >> >> >wrote: >> >> >>On Apr 8, 8:10=A0pm, John Larkin >> >><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>ftp://jjlarkin.lmi.net/BreadBoards.jpg >> >> >>>ftp://jjlarkin.lmi.net/BreadBoards2.JPG >> >> >>> John >> >> >>Are these your first pass board designs that you plan to put into >> >>production? >> >> >Nice! ;-) >> >> If I test the parts I don't fully understand, the products will work >> first pass. *That* is nice. >> >> A breadboard is not a prototype. It's a way to better understand a >> part. The "circuit" of such a breadboard is unlikely to appear in any >> deliverable product. >> >> John > >First pass design means first pass design. This should all be modeled >and you should not be wasting someones time to build these boards when >a handy dandy simulator program is available. A simulator doesn't reveal all pitfalls like latch-up effects. And in many circuits (even a switching regulator) the PCB is a part itself. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico(a)nctdevpuntnl (punt=.) --------------------------------------------------------------
From: whit3rd on 9 Apr 2010 17:00 On Apr 8, 5:10 pm, John Larkin <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > ftp://jjlarkin.lmi.net/BreadBoards2.JPG [shows a 74ACT04 with connection points] But, what's the point of breadboarding a fast gate without the required bypass capacitors on the power pins? It's not gonna behave like the final application does.
From: John Larkin on 9 Apr 2010 18:22 On Fri, 9 Apr 2010 14:00:58 -0700 (PDT), whit3rd <whit3rd(a)gmail.com> wrote: >On Apr 8, 5:10�pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> ftp://jjlarkin.lmi.net/BreadBoards2.JPG > >[shows a 74ACT04 with connection points] > >But, what's the point of breadboarding a fast gate without the >required bypass capacitors on the power pins? It's not gonna >behave like the final application does. There was a surface-mount cap between pin 14 and the solder blob on the copperclad. Looks like it broke, being tossed around in the breadboard bin for some number of years. Note that this is an RCA 74ACT04. I was astounded to see sub-ns rise and fall times, back when everybody thought that CMOS was slow. John
From: Jim Thompson on 9 Apr 2010 18:52 On Fri, 09 Apr 2010 15:22:54 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Fri, 9 Apr 2010 14:00:58 -0700 (PDT), whit3rd <whit3rd(a)gmail.com> >wrote: > >>On Apr 8, 5:10�pm, John Larkin >><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>> ftp://jjlarkin.lmi.net/BreadBoards2.JPG >> >>[shows a 74ACT04 with connection points] >> >>But, what's the point of breadboarding a fast gate without the >>required bypass capacitors on the power pins? It's not gonna >>behave like the final application does. > >There was a surface-mount cap between pin 14 and the solder blob on >the copperclad. Looks like it broke, being tossed around in the >breadboard bin for some number of years. Note that this is an RCA >74ACT04. I was astounded to see sub-ns rise and fall times, back when >everybody thought that CMOS was slow. > >John > Depending on process I generally switch from CMOS to PECL at around 500MHz... choice made from power consumption cross-over. I wouldn't run discrete CMOS packages that fast... power to drive the pin and trace capacitance really adds up in a hurry. ...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 | The only thing bipartisan in this country is hypocrisy
From: John Ferrell on 10 Apr 2010 13:22
On Thu, 08 Apr 2010 17:10:42 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >ftp://jjlarkin.lmi.net/BreadBoards.jpg > >ftp://jjlarkin.lmi.net/BreadBoards2.JPG > >John What do you use to remove the copper cladding? John Ferrell W8CCW |