I am presently using a 4 wire bus for CAN (CANH,CANL,PWR,GND). This is used all across the design for various boards. Now the cable needs to be shielded.
Would this imply using 5 pin connectors and crimping the shield into one of them (which is then connected to ground) Or is there a different way to this?
How is the drain cable connected to housing or ground when you're making a million units?
Best Answer
If a designer is worried about radiating cables then shielding is a good idea, in most designs the shield pin would be tied to chassis ground. The scheme extends the chassis and prevents EMI from interfering from the inner conductors and prevents radiation from the conductors from reaching the outside world. In either case the return currents from the radiation flow down the cable through the shield to the board, The most designs it's best to direct these currents to chassis ground and away from the PCB to prevent common mode noise.
As a designer you need to decide if radiation would be a problem which would typically result from other switching loads on your design. Just the canned bus will probably not be enough of a potential radiator to justify shielding, there should be another reason.