High-Power Electronics

With energy efficiency uppermost in engineers’ minds, improvements in high-power electronics are tremendously important. Compared to other areas of a system, significant savings are available closer to the power source, where current levels are highest.

The latest generations of power transistors such as new 40-200V MOSFETs from International Rectifier and 60V devices from ON Semiconductor reduce on-resistance to better than 5mΩ for current ratings well over 100A. Device architects are also bargaining hard with the silicon to maximise switching performance and power density – not only from discretes but also ICs such as regulators; the Exar SP7662 combines high current rating, small dimensions and high efficiency.

Cost-down, of course, is another important market demand. Prices for power silicon do not fall with die size, but packaging enhancements and functional integration can unlock system-level savings. The SP7662 with its on-chip regulator, and devices such as the Vishay SiE726DF SkyFET™ combining a MOSFET and Schottky diode, illustrate this trend by saving external components and circuitry.

Higher integration also helps engineers implement energy-saving topologies such as resonant converter designs, as demonstrated by the FSFR2100 Fairchild Power Switch. You can find out more about this and other integrated solutions in the Design Note on page 090315.

New markets, such as burgeoning demand for micro-generators to feed renewable energy into the grid system, are also driving innovations. Homeowners - as power generators - will demand the ultimate in low-cost, high-efficiency technologies.We are already seeing new components emerge, such as IR’s IRGB40xx family, which are optimised explicitly for this sector.

Gate-Drive Optocoupler Delivers Best-in-Class Common-Mode Performance

As an optocoupler capable of directly driving high-current IGBTs or MOSFETs, the Fairchild Semiconductor FOD3120 simplifies gate-drive circuitry and delivers best-in-class Common-Mode Rejection (CMR) of 50kV/µs for reliable switching in noisy environments.

With a wide operating-voltage range for maximum usability, the FOD3120 has a P-channel output stage capable of swinging close to the supply rail. The 2.5A maximum output current is adequate to control most IGBTs up to 20A/800V directly. In addition, the 1414V peak working voltage allows these devices to be used with high-voltage IGBTs.

As well as saving footprint and gate-drive complexity, the FOD3120 also boosts power efficiency through its fast switching speed, with 400ns propagation delay and 100ns pulse-width distortion allowing the use of small, low-power filters. The low, 3Ω typical, on-resistance of the output-driver stage also contributes to high overall system efficiency.

For driving smaller transistors requiring up to 1A gate drive, the FOD3150 is also available. Both devices achieve their high CMR by combining patented Optoplanar® coplanar packaging technology with optimised IC design.

FEATURES


Operating voltage range: 15V to 30V Under Voltage Lock-out (UVLO) with hysteresis Extended industrial temperature range: -40°C to 100°C Meets UL1577 and IEC60747-5-2 10mm- and 7mm-clearance package options

APPLICATIONS


AC-input motor drives Industrial inverters Solar inverters Solar inverters Induction heating Uninterruptible Power Supplies (UPS) Switched-mode power supplies

Fairchild Semiconductor / FOD3120