[CEATEC] Rohm Cuts On-resistance of MOSFET for PV Systems

Sep 16, 2011
Ikutaro Kojima, Tech-On!
The new power MOSFET
The new power MOSFET
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Rohm Co Ltd announced a new power MOSFET (metal oxide semiconductor field effect transistor) for the power conditioners of photovoltaic (PV) systems.

The company manufactured the power MOSFET, "R5050DNZ0C9," by using the silicon (Si) deep etching technology, which forms a vertical p-layer at once, and reduced on-resistance by 47% to 45mΩ (maximum value), compared with its former product.

Thus far, Rohm has developed and provided power MOSFETs for the power conditioners of PV systems. In the past, the company manufactured power MOSFETs by using the multilayer epitaxial growth method to array multiple vertical p-n junctions (super junction structure). However, because the manufacturing process of this method is complicated, it was difficult to scale down manufacturing processes and improve productivity.

This time, Rohm succeeded in reducing on-resistance by about 47% by using the Si deep etching technology, which forms a vertical p-layer at once, to scale down manufacturing process and optimize impurity density. The new MOSFET is suited for the DC-DC converters of power conditioners. And, when combined with the company's fast recovery diodes or silicon carbide (SiC) Schottky barrier diodes, it can be applied to DC-AC inverters, the company said.

Because the new product can drastically reduce loss caused by power conversion, it will greatly contribute to improving PV power generation efficiency, Rohm said. Also, the company will make the latest manufacturing technologies compatible with various circuit types to expand its line of high-voltage products such as the "PrestoMOS" series.

The power supply voltage (VDSS) and power supply current (ID) of the R5050DNZ0C9 are 500V and 50A, respectively. The standard value of its on-resistance (RDS(on)) is 34mΩ (VGS=10V). It uses the "TO247PLUS" package, which has a high radiation performance.

Rohm will start to ship samples of the R5050DNZ0C9 in mid-September 2011 at a price of ¥1,000 (approx US$13) and to mass-produce it in December 2011. The company will exhibit the new product in its booth at CEATEC Japan 2011, which will take place from Oct 4 to 8, 2011, in Chiba Prefecture, Japan.