The GF120T-24CANB is a laser wire markable, Aerospace-grade CAN Bus, approved by Garmin, for use with Garmin’s CAN Bus System architectures. CAN Bus is designed to be a 120 ohm Twinax, which means the insulation thickness is increased to achieve 120 ohms between the conductors. The increased thickness creates an issue with contact extraction because the insulation OD is larger than the contact. With GigaFlight’s CAN Bus, we have solved this issue by using a dual-wall insulation design.
The first layer of insulation is a thinner wall high temp PFA with a finished diameter less than the contact OD. The second layer of insulation is a foamed FEP that provides the separation between the wires to maintain a 120 ohms-controlled impedance throughout. A section of the foamed insulation is removed in the termination process to provide access for contact removal. An added benefit of a dual-wall construction is that the solid insulation eliminates insulation creep back, a common issue with an all foam insulation design.