Abstract: A folding amplifier in which a single tail current is used to service all differentially coupled transistor pairs in the amplifier. The input signal applied to each differential pair of transistors is used to drive a switch which controls the tail current to that specific differential pair. When a differential pair is fully switched in either direction, the associated tail current switch is open. As the input signal applied to the differential pair causes the pair to pass through its active region, the switch associated with that pair closes to allow current to be conducted through that pair. Therefore, the tail current has a path which is primarily through a single differential pair at any given time.