A 3.96μm, 124dB Dynamic Range, 6.2mW Stacked Digital Pixel Sensor with Monochrome and Near-Infrared Dual-Channel Global Shutter Capture

This paper presents a $3.96\mu\mathrm{m},640\times 640$ pixel stacked digital pixel sensor capable of capturing co-located monochrome (Mono) and near-infrared (NIR) frames simultaneously in a dual-channel global-shutter mode. A super-pixel structure is proposed with diagonally arranged $2\times 2$ sub-pixels. A gapless dual-size microlens array and NIR pass filters are utilized to retain high fill factors for both visible and NIR light, $\sim 70\%$ and $\sim 100\%$ respectively. Each super-pixel is connected to a pixelparallel ADC and two banks of 10-bit SRAMs to enable the dual-channel global-shutter operation. The power consumption at 30fps with dual-channel capture is only $6.2\mathrm{~mW}$. The Mono channel achieves a high dynamic range (DR) of $124\mathrm{~dB}$ and the DR of the IR channel is $60\mathrm{~dB}$. The sensor fits the stringent form-factor requirement of an Augmented Reality headset by consolidating Mono and NIR cameras.