MR 系統中 Micro-LED 顯示器主動式驅動 IC 之分析與高面積效率設計

Abstract

本研究針對新一代混合實境（MR）顯示應用對於高亮度、高解析度與高精度的嚴苛需求，提出一種應用於 Micro-LED 顯示的高效能驅動晶片架構設計，旨在實現對微型化 Micro-LED 陣列的高精度驅動與控制。本架構採用客製化驅動積體電路（Driver IC），成功驅動一組 5×5 的微型 Micro-LED 像素矩陣。面對微型化尺寸所帶來的微電流控制精度與像素間電流均勻性挑戰，本設計引入內部補償機制以提升數位類比轉換器（DAC）的線性度，從而有效抑制像素間的串擾（Crosstalk）並顯著提升整體的動態範圍。 在詳細的電路與佈局（Layout）設計中，分區驅動之像素單元採用高效的 2T1C（兩電晶體一電容）架構，在有限空間下實現了尺寸僅為 12×12 μm^2 的高整合度像素驅動電路，並在佈局上採用倒裝晶片封裝（Flip-Chip Bonding）技術進行整合，以確保電流的穩定保持、降低寄生效應並達成精確傳輸。灰階控制核心則整合了高效的脈衝幅度調變（PAM）與可切換式脈衝寬度調變（PWM）模式，並透過 5 位元 DAC 與位準轉換器（Level Shifter）的協同運作，精確生成 32 階灰階變化。此外，為提升系統的適應性，本晶片整合了基於低溫飄正比於絕對溫度（PTAT）技術之自偏壓（Self-Bias）電路，用以提供高穩定度的內部參考電壓，並預留外部參考電壓（Vref）輸入端。實驗結果顯示，所提出的驅動架構能有效且穩定地驅動 Micro-LED 陣列，在維持高畫質表現的同時，為 MR 顯示應用提供了一套穩健可靠的硬體解決方案。

To address the stringent demands for high brightness, high resolution, and superior accuracy in next-generation Mixed Reality (MR) display applications, this study proposes a high-performance Micro-LED display driver architecture aimed at achieving high-precision driving and control of miniaturized Micro-LED arrays. The proposed architecture utilizes a customized driver integrated circuit (Driver IC) to successfully drive a 5×5 Micro-LED pixel matrix. To overcome the challenges of micro-current control precision and inter-pixel current uniformity inherent in micro-scale dimensions, an internal compensation mechanism is introduced to enhance the linearity of the digital-to-analog converter (DAC), thereby effectively suppressing inter-pixel crosstalk and expanding the overall dynamic range. In the detailed circuit and layout design, the pixel-driving unit adopts an efficient 2T1C (two-transistor, one-capacitor) topology, achieving a highly integrated pixel driver dimension of just 12×12 μm^2.Furthermore, a flip-chip bonding configuration is introduced in the layout design to minimize parasitic effects, optimize spatial integration, and ensure stable current retention and precise transmission. The core of the grayscale control integrates a high-efficiency pulse amplitude modulation (PAM) scheme along with a switchable pulse width modulation (PWM) mode. By leveraging a 5-bit DAC and level shifters, the driver IC accurately generates 32 distinct grayscale levels. Furthermore, to enhance temperature stability and system adaptability, a self-bias circuit based on a low-temperature-coefficient Proportional-to-Absolute-Temperature (PTAT) topology is integrated to provide a highly stable internal reference voltage, complemented by an external reference voltage (Vref) input option to optimize performance across varying fabrication processes. Experimental results demonstrate that the proposed driver architecture can effectively and stably drive the Micro-LED array, maintaining high image quality while delivering a robust and reliable hardware solution for MR display technologies.