Actually you need to be careful with planes -- they can actually couple the signal from one switching line to the next. You may have better results minimizing parallelism between traces, lengths that is, and maximizing spacing between those traces.
Slowing down the edges, using termination if possible, even adding capacitance, will result in smaller voltages induced from one line to the next. Slowing the turn on of the drivers will help, at the expense of power dissipation in those transistors. On Sunday, February 22, 2015 at 10:17:23 AM UTC-6, joenixie wrote: > Hi Yall, > > I am working on a multiplexed display and am finding that for the lines > that have both of their transistors turned off, there are massive swings of > voltage that are induced on the lines. The levels are so high I get other > digits flickering in the tube and I also have neon bulbs that are attached > get lit up. > > I've read several things about this being due to timing, but this is not > the case (at least for the neon bulbs) I know this because the 'other pin', > the pin that should not light up, is the pin that gets lit up. > > I had an engineer tell me that ground plains will help isolate these to > some degree, are there any other ideas? I am using MPSA42 and MPSA92 > transistors for driving the tubes and lamps. > > Any ideas will be appreciated. > > -joe > > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/28721fbf-19a8-4f98-9fc3-a12e3149cd24%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
