AN3392 Datasheet, PDF (1/57 Pages) STMicroelectronics – The SPV1020 is a monolithic DC-DC boost converter designed

AN3392
Application note
Designing with the SPV1020, an interleaved boost converter with
MPPT algorithm
By Domenico Ragonese, Massimiliano Ragusa
Introduction
The SPV1020 is a monolithic DC-DC boost converter designed to maximize the power
generated by photovoltaic panels independent of temperature and the amount of solar
radiation. The optimization of the power conversion is obtained with embedded logic which
performs the MPPT (maximum power point tracking) algorithm on the PV cells connected to
the converter.
One or more converters can be housed in the junction box of PV panels, replacing the
bypass diodes. Because of the fact that the maximum power point is locally computed, the
efficiency at system level is higher compared to the use of conventional topologies, where
the MPPT is computed in the main centralized inverter.
For a cost effective application and miniaturized solution, the SPV1020 embeds the Power
MOSFETs for active switching and synchronous rectification, minimizing the number of
external devices. Furthermore, the 4-phase interleaved topology of the DC-DC converter
avoids the use of electrolytic capacitors, which can severely limit the system lifetime.
The SPV1020 operates at fixed frequency in PWM mode, where the duty cycle is controlled
by embedded logic running a Perturb&Observe MPPT algorithm. The switching frequency,
internally generated and set by default at 100 kHz, is externally adjustable, while the duty
cycle can range from 5% to 90% in steps of 0.2%.
Safety of the application is guaranteed by stopping the drivers in the case of output
overvoltage or overtemperature.
Figure 1. STEVAL-ISV009V1 demonstration board
May 2012
Doc ID 018749 Rev 1
1/57
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