A Compact 11-Bit Source-Driver with Adder-Embedded Hybrid DAC for Mobile OLED Displays

This paper presents a compact 11-bit source driver for mobile OLED displays to achieve high uniformity. The proposed driver consists of a 5-bit high voltage resistor string digital to analog converter (HV-RDAC), a 6-bit low voltage resistor string digital to analog converter (LV-RDAC), and a switch capacitor adder (SC-Adder). This one-stage 11-bit hybrid DAC only needs 544 transistors, resulting in a true 10-bit display effect after gamma correction. The area of the proposed 11-bit source driver is only 36.8% of that of the conventional 8-bit high-voltage source driver. Furthermore, a capacitor-exchange method is introduced to address the non-uniformities among channels caused by capacitor mismatches. As a result, the maximum deviations of voltage outputs (DVOs) between 60 channels are 3 mV (without the capacitor-exchange method) and 1.5 mV (with the capacitor-exchange method). The worst differential nonlinearity (DNL) and integral nonlinearity (INL) are 0.63 and 0.62 LSB respectively.