Capacitor coupling of GaAs defletion-mode f.e.t.s.

Integration of GaAs depletion mode f.e.t.s requires voltage level shifting between logic stages. Capacitor coupling provides such a shift without the need for additional power rails and with a high tolerance of process parameter variations; being passive, the level shifting consumes no additional power. Data can also be retained dynamically on capacitors in clocked circuits providing exceptionally low power operation. Test circuits have been fabricated which have demonstrated successfully the principles of capacitor coupling. Data from these are being used to design capacitor-coupled logic (c.c.I.) circuits for telecommunication applications. When static operation is essential, capacitor coupling can also be used to enhance the operation of conventionally coupled circuits.