Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Hot answers tagged

10

There are two aspects of a ground plane: its performance, and its appearance. The first is important. The second is not. Unfortunately, many people starting out concentrate on the second, to the detriment of the first. A ground plane should be as big as it needs to be. That is, it should be present at or near* every connector, every IC, every supply ...


3

Apart from specific cases: high voltage (where you need as big of an insulator between your signal and ground), controlled impedance (RF, high speed, the plane might help you also if done correctly) or very low noise analog circuitry. A complete and uniform ground plane bellow your signal layer should not do any harm. There might be other scenarios where ...


2

You are confusing the output impedance requirements of the LMK00105 output with the input impedance requirements of the ADCs. Let's start from the beginning: The LMK00105 has an output impedance Ro=50 Ohms. In order to match this to the TX line of 50 ohms, no series resistor needs to be used. (For the case of matching the output to a 75 ohms TX line, you ...


2

Instead of having two holes (one round and one rectangular?) you can create one plated slot. That would get rid of the internal plated wall pointed to by the red DOWN pointing arrow. Design it such that the end that you don't want fully hangs over the edge of the board. When the fab house routes the PCB, they will cut out any unwanted plating. You just ...


2

Altium (by default) exports both coordinates to the PnP file. "Mid-X, Mid-Y" (yellow coordinate system) and "Ref-X, Ref-Y" (blue coordinate system). But, from my experience, it doesn't really matter, because the operator needs to set up the pick up point and placing point manually for all the "unusual/not rectangular" parts. And, if you have both coordinates ...


2

If you check off “tented” in the via properties on the relevant side the solder mask will not be pulled back around the via, so it will look different in both the layout and when it is fabricated. See, for example, this answer. There are various reasons to prefer one over the other, but that’s outside the scope of this answer.


1

{Summary: this answer illustrates the method of DESIGNING a Ground Plane to achieve 60dB isolation between regions.} Ground planes are excellent for attracting electric field flux. Instead of your signal trace having the burden of handling all the displacement-current, the Ground Plane provides the return path for most of the displacement-current. Thus ...


1

Land patterns are almost always larger than the size of the actual component pin, although in the case of 0.5mm pitch parts this is only true for the length of the pin in many cases. Here is the component information for a 12 lead DFN from Linear Technology: The pads themselves are 0.25mm wide and 0.4mm in length. Here is the recommended land pattern: As ...


1

Workaround: klick on problematic pad, in properties, change pad shape from "rectangular" to "rounded rectangle" and set corner radius to 1% repour polygon


Only top voted, non community-wiki answers of a minimum length are eligible