At 10:37 AM -0500 2/25/2003, the pickle wrote: >At 07:28 -0800 on 25/02/03, Gamba wrote: > >>I prefer using chip caps instead of the aluminum can caps because the chip >>caps are much more reliable and also much more available. > >Question for any EEs (or former EEs, or other knowledgeable persons on the >list):
You're never a "former EE". Either you are one or you never were! > >What are the reasons to use electrolytics versus chip caps in a circuit like >this? I'm gonna take a guess and say the capacitance required >wasn't available >in a chip cap 13 years ago when the IIci and SE/30 were in development, but >what are the other issues (frequency, ripple currents, etc.) ? If you were >designing the circuit now, what would be your reasons for spec'ing chip caps >instead of electrolytics, or vice versa? The chip caps in question are electrolytics. 15 years ago surface mount caps were indeed rather limited. I've never directly dealt with surface mount design so I don't know off hand what was available when but at that time SMD caps were limited to the very low end of the electrolytic range. Certainly the 100uF or so were not available. The electrical differences between SMD and leaded Electrolytics are negligible. Assuming a surface mount board the only reason to use leaded components in general would be lack of availability, primarily due to size (either electrical rating or physical size). Alumininum can electrolytics are less commonly used now in the lower values, being replaced by tantalums mainly. 15 years ago they were still commonly used for simple supply filtering due to lower cost. But around that time tantalums were starting to replace them. Again there is no big difference between leaded and SMD. The difference is in the chemistry of the electrolyte and the construction. And both are used in leaded and SMD forms -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" -- Vintage Macs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> Vintage Macs list info: <http://lowendmac.com/lists/vintagemacs.shtml> The FAQ: <http://macfaq.org/> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/vintage.macs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
