---++ On this page we outline the possible board changes that could reduce the heater ground noise

In the following image the midlayer 3 traces are highlighted that may need to be moved to ensure that the isolator signals do not traverse over the heater ground plane. Note that I've further highlighted a region using a red ellipse. In this region we can see that the isolator signals(yellow highlight) are extremely close to the heater switch signals and perhaps its just this close proximity that causes us problems, i.e the ground may have nothing to do with our problems?*

CryoboardRev3b.jpg:

To clarify which lines are the heater switches see the following image. The heater switches are highlighted in green * CryoboardRev3bHeaterLinesGreen.jpg: Note that the traces closest to the heater switch lines are those of isolator U17 and U22.

In the following image you can see the midlayer 3 traces moved to a new location.You can also see two highlighted red regions. In the one closest to the FPGA you can see a significant portion of the copper pour removed. Is this okay? In the other region, you can also see a bottom layer trace that I moved slightly since these traces shouldnt be traversing the heater ground plane either

* CryoboardPossibleRev3c.jpg:

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This topic: CryoElectronics > WebHome > CryoboardRev3bUpdates Topic revision: r1 - 2011-06-09 - WinterlandUser

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