X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.98.4 at av02.lsn.net Message-ID: <55A7D999.5020101@ecosensory.com> Date: Thu, 16 Jul 2015 11:19:37 -0500 From: John Griessen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: geda-user AT delorie DOT com Subject: Re: [geda-user] Net attributes References: <20150712224637 DOT 2d4cc2de AT wind DOT levalinux DOT org> <55A2E9B7 DOT 9040502 AT neurotica DOT com> <20150713131707 DOT GA782 AT recycle DOT lbl DOT gov> <55A4042E DOT 5060402 AT neurotica DOT com> <55A41B30 DOT 50602 AT neurotica DOT com> <254F9AFE-1A3E-4D88-BABF-E6E0F87A56B1 AT icloud DOT com> <1436960577 DOT 1072 DOT 6 DOT camel AT ssalewski DOT de> <201507151820 DOT t6FIKYME001704 AT envy DOT delorie DOT com> <201507152007 DOT t6FK7lv8005229 AT envy DOT delorie DOT com> <24AD56C6-B7C2-4D7E-B69A-F68DBACCBFDC AT noqsi DOT com> <4DD9C29A-2105-45DC-9F17-82DA23433919 AT icloud DOT com> In-Reply-To: Content-Type: text/plain; charset=iso-8859-7; format=flowed Content-Transfer-Encoding: 7bit Reply-To: geda-user AT delorie DOT com On 07/16/2015 02:37 AM, Roland Lutz wrote: > I can currently come up with the following: > - managing voltage drop, oscillation, and heat by > - keeping trace resistance low and > - keeping common trace segments short, and > - improving signal quality in differential pairs by minimizing signal > run time differences > > I'm not an electronics engineer, though The differential pair attribs that can help also include 1. smoothness of board material, since the waveguide smoothness affects how much mismatch there is and so reflections and in a short transmission line in a system, standing wave patterns on the transmission line (differential pair). 2. definition and smoothness of the trace width so it does not have blips or sharp edges For some frequencies, (pcb antennas and feed lines), corners matter, so 3. min radius spec on a trace edge 4a. 4b. 4c. Power decoupling caps needed near a pin -- three type ranges 5. attrib category of keep away by X distance. Add it and a unique name to two nets to keep them apart.