Small signal amplifier with large signal output boost stage

A small signal amplifier with a large signal output boost stage are connected between first and second supply rails. The small signal amplifier receives first and second input signals and provides an output signal at an output node which drives a load. Under small signal conditions, the output signal varies approximately linearly with the difference voltage. However, under large signal conditions, a rail-to-rail large signal output boost stage connected to the output node is arranged to drive the output node close to the first or second supply rail as needed to provide the current demanded by the load. The large signal output boost stage is off in small signal conditions, but comes on rapidly and transfers maximum charge to the load under large signal conditions.