Abstract— A novel single-inductor dual-input dual-output
dc–dc converter with pulse width modulation control is proposed
for a solar energy harvesting system. The first input of the
converter is from photovoltaic (PV) cells and the second input
is a rechargeable battery. Apart from the conventional role
of providing a regulated output voltage to power the loading
circuits, the converter also clamps the PV cells’ voltage to the
maximum power point value to maximize efficiency. When the
PV cells harvest more power than the load, the surplus energy
is used to charge the rechargeable battery. When the PV cells
cannot harvest sufficient power, the converter schedules the PV
cells and the battery to power the load together. A test chip
was fabricated using a 0.35-μm CMOS process and measured
to verify the operation of the proposed dc–dc converter and to
demonstrate the power transfer efficiency of the solar power
management system.
Index Terms— DC–DC converter, dual-input dual-output,
energy harvesting, maximum power point tracking (MPPT),
photovoltaic (PV) cells, pulse-width modulation (PWM) control,
single inductor, solar energy.