(element 5e). – Suffix – Version (one letter, А to Я except З and Й): This optional element indicates versions of an integrated circuit with different electrical or thermal characteristics (e.g. switching speed, voltage range, etc.). It can also indicate an improved version of a device (e.g. К580ИК80 vs. К580ИК80А). Before 1980 the suffix П (P) was sometimes used to indicate a version in a plastic package instead of a ceramic package (e.g. К145ИК2П, К531ЛА19П) or a round metal can (e.g. К144ИР1П). – Version (one letter, А to М except З and Й): This element is omitted if there is only one version of a device. – Package designation (2000) (one letter, Н to Я): If this element is empty then the package is simply not specified in the designation, i.e. it could be any of the packages. Note that the letter ranges for version and package designation do not overlap. – Manufacturer designation (two letters) – Package designation (2010) (one digit or letter Н) – Package variant (one letter; А, В, С, Е, Н, К, М, Р, Т, or Х): If variants of an integrated circuit have the same parameters and package designation but differ in pinout or number of pins, then this package variant letter is added (e.g. 5400ТР045 and 5400ТР045А). Some vendors assign version letters outside the allowed range (e.g. 1395ЕН10Ж5Б). – Version (one letter; А, В, С, Е, К, М, Р, Т, or Х): This element is omitted if there is only one version of a device. Note that for the 2010 standard a different package is indicated by element 5f instead. Some vendors assign version letters outside the allowed range (e.g. 1494УА02Б3). Functional groups Functional groups (2010) Packages Package designation (1973) The package of an integrated circuit was generally not indicated in the 1973 designation, except: Bare chips without a package received a series number in the 7xx range, e.g. K712RV2-1 (К712РВ2-1). The suffix П (P) was sometimes used to indicate a version in a plastic package instead of a ceramic package (e.g. К145ИК2П, К531ЛА19П) or a round metal can (e.g. К144ИР1П). Less common than П, the suffix М (M) was sometimes used to indicate a ceramic package and Т (T) for a metal-ceramic package (e.g. К500ТМ133М and К500ТМ133Т, respectively, instead of К500ТМ133 in a plastic package). Package designation (1980) Package designation (2000) Package designation (2010) Bare chips For bare chips without a package an