====== Low temperature electronics ======

===== Collected tips =====

**Nikolai Beev/CERN** ([[https://ohwr.org/projects/ed/wiki/lowtemp?version=4|Source]])
  * Bipolar Si transistors and diodes don't work.
  * Shottky diodes usually work, their forward voltage drop increases
  * LEDs work, also with increased Vf and brightness
  * Most signal MOSFETs work. Many CMOS ICs work as well, including digital logic and a few op amps
  * Some SiGe transistors work and even become better (lower noise, higher gain and bandwidth). But they are difficult to tame and prone to oscillations in the GHz frequencies.
  * Small signal relays usually work. I've used plenty of latching Omron relays for switching things in the cold.
  * Thin film resistors with tempco of 25 ppm/K or lower work fine.
  * Thick-film resistors made of RuO2 go up in resistance and can be used for thermometry.
  * From the ceramic capacitors, only NP0 don't freeze out. Forget about high-value X7R and the kind.
  * Plastic capacitors usually work fine. Panasonic ECPU are a good SMD series with PPS dielectric - others should be fine too (PET or PP).
  * Forget about electrolytic capacitors. Only Niobium ones work somehow, but poorly.
  * Most ferromagnetic materials freeze out. Some Vitrovac tape-wound cores don't. Interestingly, circulators work too, though no one knows exactly what kind of ferrite material they use (-:
  * Standard FR4 PCB material works fine.
  * Tin/lead solder works fine, but lead-free solder likely also will work.

===== Literature & External Links=====
  * [[https://ohwr.org/projects/ed/wiki/lowtemp?version=4 | Low Temperature electronics ]]
  * PhD Thesis - Cern - \cite{Kaltenbacher:2013}
  * PhD Thesis - Delft - The beginning chapters are quite useful as reference. \cite{Homulle:2019}
  * Different electronic materials at 4K \cite{Fink.Fabing.ea:2008}
  * Commercial electronics for cryogenic use.  \cite{Buchanan.Benford.ea:2012}