Very High Brightness, High Resolution CMOS Driving Circuit for Microdisplay in Augmented Reality

Margaux Vigier (1, 2) , Thomas Pilloix (1, 2) , Bertrand Dupont (1, 2) , Guillaume Moritz (1, 2)

1 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
2 DACLE-LETI - Département d'Architectures, Conception et Logiciels Embarqués-LETI

In augmented reality applications, high brightness at high resolution is crucial to guarantee a good user experience. Explorations on efficient light sources have already been undertaken, and GaN µLEDs tend to be a good candidate. Nevertheless, micro-display driving circuits usually do not provide sufficient luminance level to offer good contrast against ambient light. We report the design and fabrication of a GaN LED microdisplay driving circuit enabling, to our knowledge, the highest brightness for such a pixel pitch and resolution. The driving circuit was designed in a 0.18µm CMOS process with 1640x1033 resolution. Each LED is controlled individually by a CMOS pixel of 9.5µm pitch. A monochrome green microdisplay enables more than WSXGA resolution and can reach 3.8MCd/m² for a fully ON micro-LED array.

Keywords: microdisplay driving circuit; GaN micro-LED; high brightness; augmented reality; pulse width modulation; HUD; near-to-eye

Domains: Engineering Sciences [physics]

Margaux Vigier, Thomas Pilloix, Bertrand Dupont, Guillaume Moritz. Very High Brightness, High Resolution CMOS Driving Circuit for Microdisplay in Augmented Reality. MWSCAS 2020 - IEEE 63rd International Midwest Symposium on Circuits and Systems, Aug 2020, Springfield, United States. pp.876-879, ⟨10.1109/MWSCAS48704.2020.9184480⟩. ⟨cea-02953371⟩