This demo shows a Power Management Unit (PMU) powered by a 1 mm² solar cell on the same substrate to rise up the harvested voltage above 1.1 V and power an off-chip NOR gate. The on-chip solar cell and the PMU are fabricated in standard 0.18 μm CMOS technology achieving a form factor of 1.575 mm².
The PMU is able to start up from a harvested power of 2.38 nW without any external kick off or control signal. The PMU features a continuous and two-dimensional Maximum Power Point Tracking (MPPT) working in open-loop mode to handle a harvested power range from nW to μW, by modifying both the charge pump topology and the switching frequency.
The chip also includes an auxiliary charge pump to generate the voltage level necessary for the control circuit, implemented as a Pelliconi charge pump of 8 stages with NMOS transistors in P-well as diodes. A Dickson charge pump with transmission gates as switches and with variable gain and capacitance per stage is also designed as the main charge pump. Finally, two relaxation oscillators are implemented to drive both charge pumps.
Authors
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- Researchers
- Víctor Manuel Brea Sánchez
- Paula López Martínez
- Diego Cabello Ferrer
- Esteban Ferro Santiago
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- Scientific programs
- Semiconductor Devices and Autonomous Sensors
