A Sub-μA fast-settling current-programmed pixel circuit for AMOLED displays

Current-programmed active matrix organic light emitting diode (AMOLED) displays have been valued for their immunity to spatial mismatch, differential aging, and temperature variation. However, the long settling time particularly at small current levels and large parasitic capacitance can be a constraint. This paper presents a new current-programmed pixel circuit that improves the settling time while preserving the stability of current programming. The pixel circuit was fabricated in amorphous silicon technology. The settling time of the new pixel circuit can be as low as 20 mus whereas the settling time of conventional current-programmed pixel is more than 2 ms.