Read-noise considerations in cryoelectric memory systems

Several sources of deterministic read noise in cryo-electric memories are discussed. Write noise and random thermal noise are not included. Noise on a single plane is first considered. Inductively coupled in-mode noise can be minimized by crossing lines at right angles and maintaining maximum distance between parallel segments of drive and sense lines. Capacitively coupled in-mode noise can be minimized by go-and-return layout. Common-mode noise is analyzed with the aid of a useful model. In-mode noise and common-mode to in-mode conversion for stacks of memory planes in simple system organizations are considered next. Reduction of these noise factors is achieved by the use of go-and-return connections of drive and sense lines between planes. Proper system operation requires a minimization of all deterministic noise components discussed.