An on-chip compensation system which is composed of an analog voltage adder and an 8-bit R-C digital-to-analog converter (DAC) is proposed for active matrix organic light-emitting diode (AMOLED) display drivers. The proposed analog voltage adder uses two groups of rail-to-rail input MOSFETs, which can work alternately, thereby extending the effective driving time (EDT) to 100%. The 8-bit R-C DAC is composed of a 5-bit R-DAC and a 3-bit C-DAC. The 3-bit C-DAC shares the capacitors with the analog voltage adder, reducing the layout area by 65% compared to the conventional method. This work is implemented in an industrial 0.18-μm CMOS technology. The measurement results show that the maximum INL of the system is 0.254 LSB, while the maximum DNL is 0.506 LSB. The layout area is only 9180 μm2 per channel.