A Low-luminance Compensation Current Driver for AMOLED Displays

Abstract

A Feedback Trans-conductance (FB-Gm) current-mode driver with a charge-transfer circuit is proposed to achieve ultra-low current drivability (<= 2 nA). By using an FB-Gm current-mode driver, both threshold-voltage and mobility variations can be compensated. In addition, an initialization technique that uses a charge-transfer circuit is proposed to handle an ultra-low current of approximately 2 nA with fast driving speed. The simulation results show that the proposed current-mode driver can compensate for 2 nA of current within 10 mu s of one-row time with 10 mu A/channel of static-current consumption. Here, 1.5 k Omega of series resistance and 25 pF of shunt capacitance, which represent double-wide ultra XGA (DWUXGA) AMOLED displays, are used for accurate simulation.