Design of digital-to-analog converter for current-mode AMOLED display drivers

Abstract

This paper presents an area-efficient 9 bit digital-to-analog converter (DAC) for current-mode AMOLED mobile display drivers. To reduce the chip size of DAC, the switched-current (SI) DAC architecture is proposed for data conversion. A high-performance current-mode S/H circuit is also suggested for the SI DAC to increase sampling speed as well as accuracy. The designed 9 bit DAC occupies only 0.014mm² per channel in a 0.35μm CMOS process and achieves a 1μs/bit conversion rate at a static current of 10μA under a 3.3V supply. The measured maximum INL and DNL are 1.6LSB and 0.8LSB, respectively. The measured maximum inter-channel DCO of 15nA was achieved. The proposed SI DAC structure is considered as the most promising candidate for the very compact-sized AMOLED mobile display driver with high grayscale and high resolution.