Galvanically isolated SpaceWire

Abstract

The physical signaling layer specified in ECSS-E-ST-50-12C as LVDS pe 644. LVDS is a current mode, differential in several benefits over other types of p particularly in the areas of noise rejection, ele generation, and power supply decoupling. W marginal immunity to common mode voltage d 1.2V, systems with physical separation, separ or a non-common ground reference can Galvanic isolation, using transformer coupli implemented by standard Ethernet interfaces, interface and reduce the sensitivity to commo an increased level of reliability to the Unfortunately, standard SpaceWire does no such isolation. Ideally, an AC coupled interfa bit transition density to keep the reference ne the voltage span. The encoding of data and scheme of SpaceWire data on a transformer layer presents a reference offset problem since randomized nor encoded use a leveling cod Worse yet, with SpaceWire's clock recovery transition density on the data line can result in transition density on the strobe line. This p development and execution of a galvanically i network using a transformer isolation approa encountered, analysis performed, and tec implement a reliable galvanically isolated Sp are presented and discussed.