A 137 dB Dynamic Range and 0.32 V Self-Powered CMOS Imager With Energy Harvesting Pixels

作者：Chiou Albert Yen Chih; Hsieh Chih Cheng^*

来源：IEEE Journal of Solid-State Circuits, 2016, 51(11): 2769-2776.

DOI：10.1109/JSSC.2016.2596765

• CMOS imager
• dual-exposure extended-counting (DEEC)
• dynamic range (DR)
• optical energy harvesting (OEH)
• programmable current-controlled threshold (PCCT)
• pulse-width modulation (PWM)
• self-powered

This work presents an 0.32 V self-powered high dynamic range (DR) CMOS imager in standard 0.18 mu m CMOS technology with dual-mode operation: imaging (IMG) and optical energy harvesting (OEH) modes. In IMG mode, a dual-exposure extended-counting (DEEC) scheme is proposed and implemented with a 5-bit programmable current-controlled threshold (PCCT) generator. By combining the DR of a short-exposure (88 dB) and an extended long-exposure (49 dB) conversions, the DEEC achieves a high DR of 137 dB. The chip consumes 10.6 mu W at 6.5 fps with 0.32 V operation and 32.1 mu W at 16.5 fps with 0.4 V operation, which results in an iFoM of 8.1 f and 9.8 fJ/pixel.code. In OEH mode, the sensing pixels turns into energy harvesting pixels with an additional global micro solar cell and corresponding mode control circuit, which generates 455 mV and 14 mu W at 60 klux (sunny day) and supports a self-powered imaging operation at 4.1 fps.

• 出版日期2016-11
• 单位清华大学