An active matrix display includes at least one data driver circuit comprising a column data line and a parallel column current line; a plurality of pixels connected in series to both the column data line and the parallel column current line comprising at least one pixel that is responsive to the column data line to drive a selected pixel current to the at least one pixel; and a loopback control circuit at the head of the column and external to the plurality of pixels that senses a voltage difference between an input column current in the current line and a voltage of a load drawing on the current line and that adjusts a data programming voltage according to the difference.