56.4: A Cascaded‐Dividing Current DAC with Fine Pitch for High‐Resolution AMOLED Display Drivers

Abstract

An 8-bit cascaded-dividing DAC that can operate at a low power supply voltage is proposed. Occupying less than one eleventh of the chip area of a conventional binary-weighted DAC with an equivalent resolution, the proposed DAC features a low operation voltage of 2 V with a good DNL and INL of less than 0.15 LSB. The proposed DAC is expected to be adequate for current-driving AMOLED drivers that have very demanding requirements of a narrow channel pitch as well as high linearity and resolution for the data channel DACs.

60.2: Low‐Power Consumptive Luminance Compensation for a Digital Driving AMOLED Display using a Multiple Output Boost Converter

“…The most impressive advantage of the cascaded-dividing DAC architecture is its area efficiency. This DAC structure enables very compact implementation of the DAC on a much smaller chip area than that of a conventional binary-weighted DAC structure using a MOSFET with an equivalent bit resolution [3]. Current from the DAC flows to the monitor pixel to sense the anode voltage variation due to OLED degradation.…”

Improved Transient Current Feedforward Output Buffer for Fast and Compact Active-Matrix OLED Column Drivers

“…A compact 9-bit segmented digital to analog converter (DAC) with a cascaded-dividing DAC structure for the 7-bit sub-DAC is used for the current DACs in each channel, which generates the data currents in the range of 10 nA-5 μA [5]. Fig.…”

27.2: A Buffer Amplifier with Embodied 4‐Bit Interpolation for 10‐Bit AMLCD Column Drivers

“…Consequently, the concept of the proposed interpolating buffer amplifier using the ratio of each tail current can interpolate the two voltages, ±ΔV and V MSB , and there is not any effect on the basic function of the original buffer amplifier. This tail current ratio can be easily achieved by the 4-bit cascaded current DAC [2]. Figure 2 shows a block diagram of column drive architecture with proposed interpolating buffer amplifier.…”

“…The 4-bit cascaded-dividing current DAC with NMOS is shown in Figure 4. If the current divider 0 including a NMOS transistor pair (M 1 , M 2 ) and a current source shown in Figure 4 is considered, then it is clear that the current divider 0 can divide the current I tail into two equal quantities [2]. Current divider 1, divider 2, and divider 3 perform the same function as current divider 0 .…”