SCIENCE

Vishay Intertechnology announced that it will present its high-performance, energy-efficient power electronics products at Intersolar Europe 2011 (Booth 119, Hall C3), being held June 8-10 in Munich, Germany.

Vishay's components meet the requirements of photovoltaic (PV) applications and end products including inverters, junction boxes, MPPT tracking systems, and monitoring systems. In line with Vishay's philosophy of being a "one-stop shop," the company's power electronics components range from resistors and aluminum and film capacitors to diodes and optocouplers. All these devices provide high reliability and a long operational life, which are especially important factors for locally distributed systems.

According to the market research company iSuppli, demand will surge over the coming years for the semiconductors used in solar panel inverters. By 2014, it is expected that the global market volume (currently $3 billion) will increase to $7.2 billion. In this context, the junction box -- the handover point between the solar cell itself and the inverter or converter -- will become increasingly important.

Vishay has continued to develop its bypass diodes especially for the junction box. The advantages of the company's Trench Schottky TMBS diodes include their extremely low forward bias loss, high reliability at a high working temperature range, and robust construction. The 25 V and 45 V devices cover a current range of 10 A to 60 A. One example is the 20WT04FN Schottky diode with a forward bias of 0.53 V at 20 A and a junction temperature of + 125 °C. With a leakage current of only 7 mA at 45 V, it is also suitable for switching converters with high switching frequencies.

The MKP1848 and MKP385 series film capacitors can be used as coupling or resonance capacitors in several PV inverters thanks to their compact construction, PCB mounting, self-healing function, and reliability. The devices offer nominal capacitance ratings from 1 to 400 microfarads with 2 or 4 connectors for PCB assembly (MKP1848), or nominal capacities of 60 to 400 microfarads and power rail connectors for direct IGBT assembly (MKP1848PCP). Vishay is also planning to release an additional mini version (MKP1848M) later this year, and a slim variant (MKP1848S) in 2012.

The new Mini Lug NTC thermistors from Vishay feature the industry's smallest mounting space of 65 mm(2)and shortest response time of less than 4 seconds. The devices enable fast and accurate temperature measurements over a range of -40 °C to + 125 °C in space-limited applications. Their small size and silver-plated nickel conductor result in a low temperature gradient of less than 5 % of delta T. Developers can choose between several electrical resistance values and can use these to optimize switching according to various criteria (self-heating, voltage output, or noise suppression).

In order to safely charge and unload energy storage devices, such as coupling, storage, and filter capacitors, Vishay's low-inductance LPS power resistors feature a power rating of up to 800 W in a compact 57 mm by 60 mm footprint. The new LPS300, LPS600, and LPS800 feature very low weight (83 grams) and are virtually induction-free ( < 0.1 microhenry). They cover a broad resistance range of 0.3 ohms to 900 kilohms and provide a dielectric strength of 12 kV RMS. With their compact size, they save valuable space on the PCB, enabling the development of smaller end products.