GaN Systems Inc - Gallium Nitride Power Conversion Semiconductors - integratedsystems

By: Gan Systems  09-12-2011

The unique island topology that we use provides for diodes, normally-off and normally-on transistors to be integrated. This allows complex structures to be built on a single chip. A commonly required structure is the half bridge shown below.

This can easily be built using the island topology and the layout is highly efficient in terms of function per unit area, and the layout matrixes perfectly to allow a very large structure to be built. However, when used in very high power, high voltage applications the half bridge drive requirements become difficult due to Miller capacitance. Using multiple, dispersed direct drivers and totally isolated input circuits as shown – a very much more practical and useful integration is achieved.

Since our island structure is designed to be totally compatible with conventional RF GaN processes, the entire MMIC fabrication capability and components are available. Microwave, digital and power devices can all be integrated on one chip.  These structures are used in the patented on-chip driver design.

Another useful integrated structure is the 3-level neutral point clamped (3-Level NPC) converter element shown below. The EMI requirements are very stringent because these structures are used in aircraft applications.

The integrated GaN structure reduces the stray inductance problem and improves the switching speed and efficiency. The new on-chip drivers and isolation circuits, with their ease of use, transform the value of the circuit.

It has been shown that a 3-level NPC converter, built with 600V devices has lower losses than a 2-level converter built with 1200V devices if the switching frequency is high enough. This is due to the reduced switching and conduction losses of the low-voltage devices which overcompensate for the increased conduction losses caused by the higher number of series connected devices in the current path. Additionally, the 3-level converter generates a better voltage and current spectrum compared to the 2-level converter. This has the ability to reduce the additional pulse width modulation losses in electrical motors.

The future of GaN in power applications is closely linked to the integration that can be easily achieved using the GaN Systems patented island topology.


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GaN Systems Inc - Gallium Nitride Power Conversion Semiconductors - partnering

In addition to our own devices, we partner with other semiconductor companies to develop leading edge complementary products and in the development and manufacture of their own products. In conjunction with our layout designs we can offer process and packaging alternatives for those wishing to establish a GaN capability. To request more information on our partnering opportunities please contact our Head office or European office directly.


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GaN Systems Inc - Gallium Nitride Power Conversion Semiconductors - transistors

We expect there will be a five times improvement over the next five years and GaN transistors will achieve specific on-resistance results better than 0.6 milliohm.cm.sq. It is clear from both the Si and SiC results that these technologies are at or near their technology limit in the case of the simpler field effect structures.


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GaN Systems Inc - Gallium Nitride Power Conversion Semiconductors - products

Integrated single chip half-bridge structures, full-bridge diode arrays, and GaNTetrode™ devices for power and RF applications are also compatible with our unique island structure. Cool Switching™ – that summarizes the benifits of our unique island based topology and products – highly efficient low-loss diodes, transistors and integrated systems.


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GaN Systems Inc - Gallium Nitride Power Conversion Semiconductors - diodes

GaN Systems’ Cool Switching™ high power diodes provide formerly unheard-of efficiencies, small size, no intrinsic charge storage and very low heat losses. In terms of overall system cost, our GaN based diodes are cost competitive with silicon, while offering superior performance to silicon carbide devices.