No abstract

No abstract

No abstract

This paper proposes a 10-bit linear gamma digitalto-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. Keywords-AMOLED, digital-to-analog converter (DAC), large-sized AMFPD, small area DAC, source driver IC, voltage adder.

We investigated the characteristic variation of an integrated thin-film resistor (TFR), which is composed of silicon chromium (SiCr), according to process conditions and its effects on analog circuits. To improve TFR properties, such as temperature coefficient of resistance (TCR) and mismatch, the integrated TFR was examined under various process conditions. First, the sputtering power and the annealing temperature were optimized to control the TCR property. Secondly, the etching time and the dummy pattern were optimized to enhance the mismatch property. The measured TCR is −3.9 ppm/°C and the calculated mismatch slope from the standard deviation of resistance mismatch is 0.34%·µm. These results show that the fabricated TFR had near-zero TCR and a high matching constant. To verify the TFRs effects on analog circuits, low-pass filters (LPFs) were fabricated and measured as a test vehicle; the use of the optimized resistor considerably improved the performance of the resulting LPFs.Index Terms-Integrated thin-film resistor (TFR), low-pass filter (LPF), mismatch, silicon chromium (SiCr), temperature coefficient of resistance (TCR), TFR dummy pattern, TFR.