Renewable energy ICs reduce photovoltaic system cost

National Semiconductor Corp. introduces 10 new SolarMagic integrated circuits (ICs), the first in a series developed to reduce cost, improve reliability, and simplify design of photovoltaic (PV) systems. Ranging from a full-bridge gate driver to a micropower voltage regulator, the new ICs are well suited for a variety of photovoltaic electronic applications, including those found in microinverters, power optimizers, charge controllers, and panel safety systems.

The new SolarMagic ICs were developed to meet photovoltaic renewable energy-grade qualification requirements. Each IC is engineered specifically for demanding rooftop environments that range from extreme cold to severe heat, and each passes rigorous testing with enhanced reliability specific to solar requirements. In addition, the ICs ensure longterm operation, developed to meet and exceed the 25-year life expectancy of photovoltaic modules.

Collectively provided as a complete design, SolarMagic ICs increase energy harvest, reduce cost per kilowatt-hour, and improve safety in junction boxes and other types of enclosures. Used independently, the ICs provide high voltage and high current gate drive for microinverter or power optimizer designs.

A full set of reference designs and application notes help the designer quickly develop a complete photovoltaic system. Each reference design includes an evaluation board, bill of materials, and schematic.

Technical features of SolarMagic ICs:

• MPPT controllers - For distributed PV power optimization applications providing maximum power point tracking (MPPT), National offers the SM72441 and SM72442 programmable MPPT controllers. Features include voltage and current diagnostics, integrated four switch buck-boost converter control, overvoltage/overcurrent protection, and an I2C interface.
• Gate drivers – For power processing circuitry in power optimizers, microinverters, and charge controllers, National offers the SM72295 full-bridge and SM72482 dual 5A compound gate drivers. The drivers can drive four discrete MOSFETS in a full-bridge configuration and each includes a high side overcurrent sense amplifier with high sink and source current capabilities.
• Voltage regulators - For a variety of bias rail applications used in power optimizers, microinverters, and charge controllers, National offers the SM72485 switching regulator with constant-on-time technology that enables an operating range up to 100 V at high conversion efficiency. National also offers the SM72238 5-V low drop out (LDO) regulator for lower power.
• Sensing and detection – National offers a variety of products for ancillary circuits commonly found in distributed PV power optimization and battery charging applications for protection, sensing, supervisory, and control. The SM72240 is a supervisory reset circuit. The SM72375 is a dual micropower rail-to-rail input CMOS comparator. The SM72480 is a preset temperature switch and sensor that provides high accuracy. The SM72501 precision CMOS, RRIO, wide supply range amplifier provides low offset voltage along with low input bias current.