A 10-Bit Low-Power High-Color-Depth Column Driver With Two-Stage Multi-Channel RDACs for Small-Format TFT-LCD Driver ICs

Abstract

This study proposes a 10-bit low-power high-color-depth LCD column driver IC with two-stage multi-channel RDACs and switch resistance compensation. The design removes intermediate buffers from two-stage RDACs and uses global reference buffers to isolate the global resistor string and output channels. Because the global resistor string is isolated from output channels, the global resistor string can use a larger resistance value to achieve lower power consumption. This study proposes a class-AB buffer for the global reference buffers to compensate for the errors caused by the voltage drop on switches connected in series with the channel resistor string. The channel resistor strings also reuse the output stage current of the global buffer to reduce power consumption. A prototype of a 200-channel column driver was fabricated using 0.18-m/0.35-m CMOS technology with the worst DNL/INL being 1.2/1.1 LSB. The proposed 10-bit DAC occupies only 66 % of the area of a conventional 8-bit RDAC using the same technology. The 200-channel column driver consumes a total static current of only 0.38 mA.

Digitisation of Conventional Water Meters using Automated Number Recognition

“…Adding the electric field onto the LCD pixels makes the pixels work [56], and the electric field is generated by electrode potential at both sides of this display pixel. It is easy to build a direct current field on the pixel, but the direct current field will result in reaction liquid crystal materials and electrode ageing, quickly shortening the LCD display life [57]. We choose to use PCF8577C as the LCD driver IC.…”

High-Speed Column Driver IC Having Buffer Amplifier with Embedded Isolation Switch and Compact Adaptive Biasing for Flat-Panel Displays

“…Large-sized, high-resolution, flat-panel display (FPD) monitors and TVs require lowpower, small-area, high-slew-rate amplifiers as column (data or source) drivers [1][2][3][4][5][6][7][8][9][10]. As display panels are becoming larger and require higher resolution, driving an FPD will be challenged because the driver has to drive heavy R and C panel loads more effectively, with a faster settling time, less power, and smaller area.…”

“…The R and C panel loads driven by a buffer amplifier are ever increasing with the advancement of FPD technology, whereas the constraint on settling time is becoming tighter. A column driver for a large FPD typically requires receiver comparators, data registers, and shift registers, which are composed of low-voltage transistors, gamma reference voltages and digital-toanalog converters (DACs), which are composed of middle-voltage transistors, level shifters and output buffers with output-polarity switches, which are composed of high-voltage transistors [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Recently, the column driver may include a delay-locked loop (DLL) or phase-locked loop (PLL) for high-frequency operation, analog-to-digital converters (ADCs) for compensating the organic light-emitting diode (OLED) display degradation, and a temperature sensor for monitoring the ambient temperature.…”

“…Recently, the column driver may include a delay-locked loop (DLL) or phase-locked loop (PLL) for high-frequency operation, analog-to-digital converters (ADCs) for compensating the organic light-emitting diode (OLED) display degradation, and a temperature sensor for monitoring the ambient temperature. The driver sub-system can use either an analog [1][2][3][4][5][6][7][8][9][10][11][12]14] or a digital [13] approach as its driving scheme. The thin-film transistor liquid-crystal displays (TFT-LCDs) adopt inversion driving methods (column, frame, line, dot, and 2-dot inversions) to alternate the polarities of liquid crystal (LC) cells in regard to common electrode voltage (V COM ).…”

Survey on Single Stage Amplifiers for Column Drivers in Active Matrix LCD Panels Leading to a Highly Linear Rail-to-Rail Robust Amplifier

“…To meet the tight demands of the market, it is crucial to develop proper driving schemes to insure the highest display quality and lowest power consumption [12]. Considering that pixels are driven through the use of row and column drivers [13]. Where column drivers deliver image data to each pixel, thus column drivers are a crucial part of the driving system [12].…”