X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com X-Injected-Via-Gmane: http://gmane.org/ To: geda-user AT delorie DOT com From: Kai-Martin Knaak Subject: Re: [geda-user] gschem: assigning multiple pcb pad numbers to one schematic pin? Date: Wed, 29 Jul 2015 01:45:36 +0200 Lines: 29 Message-ID: References: <55B7849E DOT 6070401 AT envinsci DOT co DOT uk> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit X-Complaints-To: usenet AT ger DOT gmane DOT org X-Gmane-NNTP-Posting-Host: a89-182-251-185.net-htp.de User-Agent: KNode/4.14.1 Reply-To: geda-user AT delorie DOT com Matt Rhys-Roberts (matt.rhys- roberts AT envinsci DOT co DOT uk) [via geda-user- Ht4Cp5ncgjRBDgjK7y7TUQ AT public DOT gmane DOT org] wrote: > The default SOT223 footprint (3 legs and a large pad) has pads > numbered 1~4, but the device I want to use it with only has 3 > different pins effectively. I don't want to get into editing the FP > it if I don't have to. > > My device has pins numbered 1,2,3 and the pad is connected to pin 2. This is the common set-up for transistors and regulators. I have yet to get my hands on a device that does not have the middle pin connected to the cooling pad. > Can I modify the schematic symbol so that pin 2 can be connected to > pads 2 and 4 somehow? I went for the complementary solution and designed my SOT223 footprint with only pin numbers 1, 2 and 3. The large section that solders to the cooling pad also gets pin number 2. For better heat dispersion I added another big pad on the bottom side. It connects to the top with a couple of thru hole pins. The thru hole pins and the big bottom bad get also pin number 2. This footprint was able to dissipate heat quite efficiently. ---<)kaimartin(>---