Compact and power‐saving polysilicon data driver with common‐decoder DA converter (CD‐DAC)

Abstract

A common-decoder architecture for a data-driver circuit fabricated by using a polysilicon process has been developed. The architecture achieves a compact circuit and low-power consumption. In application to an integrated polysilicon data driver for small-sized displays, this architecture reduces the area of the data driver by removing the vertical bus lines that occupy a large area. It also suppresses the power consumption of the data bus by reducing the number of driven lines in the data bus during word-to-word transitions from six to two. By using a conventional 4-µm design rule, we fabricated an active-matrix OLED (AMOLED) panel with an integrated six-bit data-driver circuit with 384 outputs. The driver circuit had a height of 2.6 mm and a pitch between output lines of 84 µm. The maximum power consumption of the driver was only 5 mW, i.e., 3.8 mW for logic-data transfer and 1.2 mW for reference-voltage source. Furthermore, we also fabricated an active-matrix LCD (AMLCD) panel including driver circuits of the same type as the integrated elements. Six-bit full-color images were successfully displayed on both panels.