Bipolar binary adder for three input variables - uses differential transistor pairs to obtain sum and remainder signals for output matching stage

摘要

Three input variables are applied to a first stage circuit comprising differential pairs of transistors for each of the variables and their complements. A current generator whose base is controlled by a reference voltage is connected into the emitter circuit of the series connection of the differential transistor pairs. This stage produces a sum and its complement of the inputs. - A second stage comprises differential transistor pairs and also receives the three input variables and their complements to produce a remainder signal and its complement. These transistors have a current generator in the emitter tail circuit. The sum and remainder signals are applied to a third stage comprising series connected transistors forming matching stages for the individual signals. The outputs are at the standard logic levels for following circuits.(0/4)