-----Original Message----- From: Ian Wilson [mailto:[EMAIL PROTECTED]] Sent: Tuesday, May 21, 2002 4:36 PM To: Protel EDA Forum Subject: Re: [PEDA] hidden pin problem
<snip> I recommend that anyone using the Protel libraries copy the component from the lib into their own library and unhide all the hidden pins on all parts and the rejig the power pins to either one part having the single set of power pins <snip> <snip> Ian Wilson I tend to agree with showing all pins and until recently this seemed straightforward. For instance, on a dual op-amp package, I would have visible power pins on the first op-amp and no power on the other op-amp in the package. ( this is not without problems - how many times have you been burned when an op-amp has been rotated to flip the + & - inputs, thereby putting the negative power rail on top which is usually the positive power rail... but I digress) Our department has started using the Simulation and I have had to update our libraries to support this. It turns out that an op-amp without any power pins does not simulate, the Spice netlist builds each op-amp with power pins for each instance. Without thinking it through, I popped in some hidden power pins on op-amp B which made simulation work, but now the PCB netlist suffers from the 'hidden' nets syndrome. Resulting in two net assignments for the op-amp power pins! So it would appear to me that I have to put visible power pins on every op-amp in a package to make it work for simulation and avoid hidden pin syndrome. While this is the lesser of evils, it opens up the possibility of having different power voltages assigned to the same package. sigh Anyone have a more elegant solution? Duane Foster * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
