33.1: Invited Paper: P‐type Low‐Power Low‐Temperature TFT‐LCDs

A low power poly-Si gate and data driver circuits employing ptype low temperature poly-Si (LTPS) TFTs are proposed and verified by simulation and measurement. We have designed a 5V driven p-type level-shifter and it achieves a wide range output of  8~10V. A new p-type latch employing complementary clock compensation is proposed and the latch stores the low voltage (5V) data bits (D and D') without an output voltage loss. A simple and new source-follower type poly-Si analog buffer with fast charging is also designed and measured. P-type poly-Si fully integrated circuits on glass substrates may provide cost benefits and improve panel reliability.

Section: Low Voltage Level-shiftermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

21.2: A Low-Voltage P-type Poly-Si Integrated Driving Circuits for Active Matrix Display

Nam

Jung

Lee

et al. 2005

“…To integrate p-type low temperature poly-silicon (LTPS) driving circuits on glass has been paid more and more efforts in order to combine the merits of cost competitiveness of p-type processes and circuitry integration ability of LTPS technology [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

22.2: Invited Paper: System-on-Glass LTPS LCD using P-type TFTs

Yeh

Sun

Pai

et al. 2006

We have developed a p‐type 2.2” QVGA LCD panel with integrated level shifters, shift registers, positive and negative‐voltage DC‐DC converters, and a de‐multiplexer for mobile applications. Novel low‐power p‐type shift registers and level shifters have been also integrated on the glass to reduce the power consumption. Moreover, positive and negative‐voltage p‐type DC‐DC converters are also built on the glass to supply the power for the panel. In consequence, the operation voltage of the driving IC outside the panel can be reduced to 5V, and high‐voltage Si processes for the IC can be avoided.

“…On the other hand, one merit of LTPS thin film transistor (TFT) is the ability to integrate the peripheral circuits on the panel due to its high current driving capability [1] [2]. Therefore, some studies start to focus on P-type circuit integration try to merge these two merits [3]- [7]. However, to adopt P-type process will affect the integration degree of peripheral circuits because of the power consumption issue.…”

Section: Introductionmentioning

confidence: 99%

“…However, to adopt P-type process will affect the integration degree of peripheral circuits because of the power consumption issue. Otherwise, the additional clock signals in different phases [3] [5] or redundant voltage source [4] has to be provided from the system to suppress the steady current. However, the fore-mentioned methods will increase the design complexity and power consumption of the external IC, which will limit the application of P-type panels in mobile field.…”

Section: Introductionmentioning

confidence: 99%

P-173L: Late-News Poster: A 2.2-inch QVGA System-on-Glass LCD Using P-Type Low Temperature Poly-Silicon Thin Film Transistors

Yeh

Sun

et al. 2005

We have developed a P-type 2.2" QVGA LCD panel with integrated level shifters, shift registers, DC-DC converter, and demultiplexer for mobile application. We also have proposed a novel P-type level shifter to decrease the voltage amplitude of input control signals to fulfill the low power consumption requirement. Besides, we also have integrated a P-type DC-DC converter on the panel to supply the power for the panel. Therefore, the voltage amplitude of control logic signals for our P-type panel can be reduced to 5V, and the IC architecture can be greatly simplified. IntroductionP-type low temperature poly-silicon (LTPS) process has the ability to provide more cost competitiveness than LTPS CMOS process. On the other hand, one merit of LTPS thin film transistor (TFT) is the ability to integrate the peripheral circuits on the panel due to its high current driving capability [1] [2]. Therefore, some studies start to focus on P-type circuit integration try to merge these two merits [3]- [7]. However, to adopt P-type process will affect the integration degree of peripheral circuits because of the power consumption issue. Otherwise, the additional clock signals in different phases [3][5] or redundant voltage source [4] has to be provided from the system to suppress the steady current. However, the fore-mentioned methods will increase the design complexity and power consumption of the external IC, which will limit the application of P-type panels in mobile field. Therefore, to develop a low-power and low-voltage platform for P-type panel application is an indispensable way to enjoy the good of P-type process without bearing the low integration drawback.In this work, we have proposed a 2.2" QVGA P-type panel with the integrated shift registers, level shifters, demultiplexer, and DC-DC converter. We also have proposed a novel low power Ptype level shifter. Through integrating this level shifter on the panel, the voltage amplitude of control signals can be greatly reduced without adding any redundant control signal or voltage source. As a result of this, the voltage amplitude of the external IC control signals can be down to 5 Volt without increasing the design complexity of the external IC. Moreover, we also have integrated a P-type negative voltage DC-DC converter on the substrate. Therefore, the size of the IC can benefit by removing the area-consuming level shifter and the negative voltage DC-DC converter from the glass. The peripheral circuit integration level of this P-type panel can compete with the CMOS TFT panel for mobile application. As a result, this 2.2 inch QVGA panel can not only have the merit of P-type process cost competitiveness, but also have the same circuit integration level as the CMOS TFT panel. Architecture of the LCD PanelThe block diagram in figure 1 (a) shows the architecture of the LCD. A P-type negative voltage DC-DC converter, shift registers, demultiplexer, and level shifters are integrated on a 2.2-inch QVGA (240x320) panel. Comparing with the previous works, the proposed 2.2-inch P-type pa...