-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 At 07:29 AM 6/7/00 -0700, Harold M Hallikainen wrote: > Another approach I've used is the micro-Q capacitors from Circuit >Components, Inc. (see http://www.cci-msc.com/mq1000/mq1000.htm). These >capacitors fit under the chip or socket. They use the same through holes >as the power pins to the chip. The result is VERY SHORT leads (and low >inductance). > On most designs now, I've got a ground plane on both sides of the board. >A ceramic bypass capacitor is right at the power pin on the chip (typical >trace length is 0.1 inch). The other side goes to the ground planes. These are the ones that are a large slab with leads? Definitely better than the "axial 0.1uF in a socket" and possibly as good as an SMD part mounted at the ground pin. Ideally, you'd feed the VCC side of this with a relatively narrow track (I use 8 mils for logic) which tends to keep the noise isolated to that node. As long as the chip ground is at the same point as the cap ground, then I'd say these are a good (if somewhat pricey) answer. I think that an SMD cap on the solder side with proper routing would be within a dB or so and less expensive. Haven't measured these yet, but they do have nice low Z looking construction. - -- Are you an ISP? Tired of spam? www.spamwhack.com A pre-emptive strike against spam! Where's Dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9 -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.2 for non-commercial use iQA/AwUBOT6YsYFlGDz1l6VWEQK1AwCeOLSZ11GteobITdjn962WaMGkLioAoL43 O7h48JzeoG7o7Zgz+yHj6DIk =xdlH -----END PGP SIGNATURE-----