Certain types of complementary metal-oxide-semiconductor (CMOS) and hi
gh-speed complementary metal-oxide-semiconductor (HCMOS) integrated ci
rcuits (ICs) were investigated at temperatures T from 1.4 to 297 K. Ba
sic parameters of integrated multiplexers operating at liquid helium t
emperature were measured. Integrated circuits of the K1564 and 74HC fa
mily fabricated by HCMOS technology exhibited the best characteristics
at T = 4.2 K.