A small area 10-bit linear gamma DAC with voltage adder for large-sized active matrix flat panel displays

摘要

This paper proposes a 10-bit linear gamma digital-to-analog converter (DAC) of source driver ICs for large-sized active matrix flat panel displays (AMFPDs). The proposed DAC employs the voltage adder to reduce the area of source driver IC. The voltage adder not only reduces the size of 7-bit DAC to about half by adding the fixed one least significant bit (LSB) voltage but also quickly settles the output to the target voltage by its pre-charged output. To verify the performance of the proposed DAC, the simulation and layout are performed with a 55-inch full high-definition active matrix organic light emitting diodes (AMOLED) display. The simulation result of the proposed DAC shows INL of 0.98 LSB and DNL of 0.69 LSB. The proposed DAC uses only 57.3% of number of transistors compared to the conventional 10-bit DAC with a 3-bit embedded amplifier, which results in reducing the area of source driver IC for AMFPDs significantly.