Reconfigurable 96×128 active pixel sensor with 2.1µW/mm2 power generation and regulated multi-domain power delivery for self-powered imaging

We present an energy harvesting system comprising a dual purpose CMOS active pixel sensor (APS) array, and a combined energy extractor and multi domain voltage regulator on a single die in 130nm technology. The reconfigurable image sensor is a 128 × 96 pixel array. The array captures image and is reconfigured to form an on-chip photovoltaic cell to harvest energy. It generates 2.1μW peak power at 300mV with 200klux illuminance. The generated voltage is used as the input of the switching energy extractor that boosts the voltage up to 3.3V and stores the energy in the storage element (battery/super capacitor). The stored energy is then supplied to the load at three independent domains using the single inductor multi-output (SIMO) buck regulator. Both the SIMO buck and the energy-harvesting boost use the only inductor in the system through internally managed time-multiplexing mechanism. This prototype demonstrates a solution for low frame rate, energy autonomous imaging applications including distributed wireless sensor node and IoT electronics.