Differential amplifier with rail-to-rail input capability and controlled transconductance

摘要: A differential amplifier operable between a pair of supply voltages that define rail-to-rail range contains portions (20 and 22) together provide representative signal amplification across the range, although neither portion individually does so. current control (24) regulates operating currents (IN Ip) for in such way transconductance can be controlled desired manner as common-mode part (VCM) input (VI+ VI-) varies range. The is typically to largely constant. summing circuit (26) selectively combines internal (IA, IB, IC, ID) from generate at least one output (IO+ IO-) signal.