51.1: A DC‐DC Converter Circuit Integrated into a Poly‐Si TFT LCD Containing a 6‐bit DAC

Abstract

A DC-DC converter composed of charge pumps and regulators has been integrated into a poly-Si TFT LCD that also contains a 6-bit DAC. It has the ability to supply regulated voltages to the 6bit DAC and to the LCD's gate driver circuit.

LTPS circuit integration for system‐on‐glass LCDs

“…We have proposed high-efficiency charge-pump DC-DC converters for SOG-LCDs in 2004. 12 To obtain high power efficiency and reduce output voltage drop, switched-capaci-tor-type charge-pump circuits are always adopted for LTPS DC-DC converters, [2][3][4]12 instead of Dickson-type chargepump circuits. 13,14 Figures 5(a)-5(d) shows circuit implementation of 2VDD, 3VDD, -VDD, and -2VDD voltage boosters, respectively, which are mostly used in SOG-LCDs.…”

“…Several papers have described the implementation of SOG-LCDs using LTPS technology. [1][2][3][4][5][6][7] However, thus far it is still difficult to achieve high-resolution LCDs with multi-bit colors and low power consumption using SOG. This is because LTPS TFTs have poor characteristics, such as a higher threshold voltage, lower mobility, and larger variation, and are fabricated with a larger design rules in comparison with those of single-crystal-Si LSIs.…”

54.1: A Low‐Power SOG LCD with Integrated DACs and a DC‐DC Converter for Mobile Applications

“…In our previous circuit we used regulators to supply voltages to both the data driver and the gate driver [4]. This was to ensure voltage stability even when variations in images being displayed resulted in fluctuations in load currents.…”

“…To this purpose, poly-Si thin film transistor (TFT) technology has been used to integrate display driver circuits (e.g., gate driver and digital-to-analog converter (DAC) circuits) on glass substrates [1], and such integration has come to include charge pumps for supplying power to gate driver circuits [2] [3]. In our previous work, we proposed an integrated DC-DC converter composed of charge pumps and regulators to drive such data driver circuits as DACs [4].…”

Fabrication of Novel Three-Step Drift-Doped Low-Temperature Polycrystalline Silicon Lateral Double-Diffusion Metal–Oxide–Semiconductor Using Excimer Laser Crystallization

“…ECL is the most promising technique for growing large poly-Si grains and it cannot cause damage to the glass substrate because of a large absorption coefficient for a-Si in the UV light region (optical absorption coefficient > 10 6 cm À1 ). [16][17][18][19] The grain boundary causes many defects, which act as trap states in the band gap and degrade the electrical characteristics of devices, such as threshold voltage, mobility, and subthreshold swing. In this work, we focused on the study of LTPS-LDMOSFETs and compared LDMOS with LIGBT.…”