Quote: (Originally Posted by
Genesis)
Oh now c'mon. That's not true. There are ways to prevent ESD damage and they're not exactly esoteric.
We had an offline discussion on the ESD issue. The short of it is that you use capacitor and resistor as shunts for ESD, whereas we use series methods because ESD is a discharge spike of 1ns, followed by 100ns decay from the body, and the inductance in shunts means they work poorly. For example, most capacitors are actually inductors at these frequencies (just check the self resonant frequency of the capacitor).
There are lots of ways of skinning a cat, and lots of simple cheap solutions to the ESD issue. We both agree this is not esoteric stuff, but basic things any decent designer does to external inputs. The easiest one of all is to fit SMB connectors instead of Molex so the gnd makes contact before the signal pin.
The tracking inside the board is not for ESD: it is to prevent the power supply being coupled to the sensor tracks anywhere. Tracks are covered by solder resist, but if the power supply does get to them through heavy condensation or worse, a flood, then the sensors are stuffed.
Alex