An Area-Efficient 10-Bit Source-Driver IC With LSB-Stacked LV-to-HV-Amplify DAC for Mobile OLED Displays

Abstract

This article presents an ultra-compact 10-bit source driver IC (SD-IC) developed for mobile organic light-emitting diode (OLED) displays. The proposed LSB-stacked low-voltage (LV)-to-high-voltage (HV)-amplify digital-to-analog converter (DAC) allows the area-consuming 8-bit voltage selector to be implemented with compact LV transistors (LV-MOS) as well as obtains an additional DAC resolution of 2-bit by dissipating little die area. By virtue of the LV-MOS voltage selector, level-shifters (L/S) can also be eliminated, further lowering the column channel size. In addition to its compactness, the proposed SD-IC merits a high uniformity attained from a mismatch-insensitive switched-capacitor (SC) 4 × -multiplier and a globally sampled 2-bit stack-up voltage. A technique to elaborately cancel the offset of the buffer amplifier is also included in this work. The prototype 600-channel SD-IC was fabricated in a 130-nm 1.5/5-V CMOS technology. The maximum differential nonlinearity (DNL) and integral nonlinearity (INL) were measured to be − 0.39 and 0.9 LSB, respectively, with a 1-LSB voltage of 4.1 mV. An achieved deviation of voltage outputs (DVOs) was 4.82 mV, which is low enough to be comparable to the 1-LSB voltage. The proposed 10-bit channel size of 2688 μm2 is a 65.2% reduction in comparison to conventional 8-bit SD-IC.