This paper demonstrates a programmable pulse width shift register using depletion mode oxide TFTs for high resolution and high frame rate displays. The proposed shift register is adopted for a pre-charging scheme in a multi-frame-rate display panel because the gate pulse width is programmable only by adjusting the start pulse width without any additional clock signals and reconfiguration of interconnection. To cope with the depletion-mode issue that TFTs are turned on even at zero gate-source voltage, the modified circuits are introduced, compared to the previous LTPS version of a programmable shift register. In addition, the power consumption is reduced significantly by means of a new inverter circuit. The proposed circuit is verified by SPICE for 50 stages and the estimated power consumption is 5.01 mW in the case of two line time pulse width, which is lower than 9.76 mW of a previous oxide TFT overlap shift register by 48.7%.
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