Gallium Nitride (GaN)
CoolGaN™ 400V and 600V e-mode HEMTs
With CoolGaN™ Infineon brings GaN technology to the next level.
Gallium Nitride (GaN) offers fundamental advantages over silicon. In particular the higher critical electrical field makes it very attractive for power semiconductor devices with outstanding specific on resistance and smaller capacitances compared to silicon switches, which makes GaN HEMTs great for high speed switching.
Infineon CoolGaN™ technology is built to fully exploit the benefits of GaN. Our CoolGaN™ 400V and 600V e-mode HEMTs are offerd for consumer and industrial applications such as server, telecom, wireless charging, adapter and charger, and are qualified well beyond the standards. Infineon’s CoolGaN™ enhancement mode HEMTs are based on the most robust and performing concept on the market and will add significant value to a broad variety of systems across many applications.
How does a GaN transistor work?
Using a p-GaN gate structure, Infineon CoolGaN™ works similar to conventional silicon MOSFETs with enhancement mode gate drive bias. When a positive gate voltage is applied, electrons are accumulated and form a low resistance channel in a lateral twodimensional electron gas (2DEG) layer between drain and source.
Unlike silicon MOSFETs with PN junction body diodes, GaN devices conduct reverse current as one of the switching states, eliminating reverse recovery charge which is a major source of switching noise.
CoolGaN™ transistors are the power devices with the best performance available on the market. They are built with the most reliable GaN technology, tailormade for the highest efficiency and power density in switch mode power supplies.
Infineon's CoolGaN™ 400V and 600V e-mode HEMTs enable 98%+ system efficiency and help customers to make their end products smaller and lighter. The impressive Figure or Merits (FOMs) of CoolGaN™ 600V transistors translate into valuable application benefits.
Infineon GaN quality
The qualification of GaN switches requires a dedicated approach, well beyond existing silicon standards: Infineon holistically aproaches the quality of GaN devices and qualifies GaN devices well beyond the standards without any compromise on long term quality and reliability.
Thourogh understanding of mission profiles and verified failure models, based on accelerated test conditions are integral part of our qualification approach and ensure that lifetime and quality are fully met in the target applications.
CoolGaN™ 600V e-mode HEMTs
The CoolGaN™ 600V is tailored for telecom, datacom and server SMPS as well as other industrial and consumer applications. It is the most robust and performing concept in the market. The CoolGaN™ portfolio is built around high performing SMD packages to fully exploit the benefits of GaN. With its superior switching performance it is first choice for use cases where highest efficiency or power density are required.
The chosen enhancement mode concept offers fast turn-on and turn-off speed, a clear path towards integrationon on chip or package level as well as a solid cost-down roadmap.
CoolGaN™ 400V e-mode HEMTs
Coming with all the benefits of the CoolGaN™ 600V technology the CoolGaN™ 400V e-mode HEMTs portfolio is targeting specifically the class D audio market.
CoolGaN™ in the applications
GaN will add significant value to a broad variety of systems across many applications. Infineon's CoolGaN™ 400V and 600V e-mode HEMTs target consumer and industrial applications such as server, telecom, wireless charging, audio, adapter as well as charger, with the most robust and performing concept in the market.
The prospect of wirelessly charging our mobile devices has been around for years and recently became a reality with the proliferation of inductive wireless charging technology. However, to make wireless charging truly ubiquitous and offer improved end-user convenience (e.g., improved freedom of positioning), wireless charging solutions need to further evolve and likely will transition to magnetic-resonance technology over time. For the latter, high transmission frequencies (multiple MHz) are required and pose significant challenges to standard silicon power technologies within the transmitter and the receiver devices.
Due to its significantly reduced parasitic capacitances, CoolGaN™ technology is the ideal choice when switching at frequencies in the MHz range (e.g., 6.7MHz as required by the A4WP wireless charging standard).
Various topologies have been discussed to enable inductive wireless charging systems where Zero-Voltage-Switching (ZVS) class D and differential class E are the main topologies of choice. Both topologies reduce switching losses by transitioning between on and off-switching position of the power devices at zero-volt across the respective power switch. In the class D ZVS topology lower breakdown voltage devices can be used, thereby increasing the overall system efficiency. In the class E topology; however, simpler driver architecture (low-side only) and only a single switch per class E branch offer the prospects of reduced system cost. CoolGaN™ is ideally suited to address both topologies by either maximizing overall system performance (in class D implementations) or reducing overall system solution cost (in class E implementation).
Infineon’s CoolGaN™ 600V devices have been successfully tested in a 16W class E wireless charging demonstrator system as well as in customer implementations operating at 6.78MHz.
For more information on using CoolGaN™ in wireless power systems, please contact your Infineon representative.
Class D audio amplifier
Class D audio amplifiers have practically eliminated class A/B amplifiers as they offer greatly improved energy efficiency, and thereby enable small form factor designs for even high power amplification. In addition, class D audio amplifiers theoretically can reach 0% distortion and 100% energy efficiency in case the power switch in the class D stage is an ideal switch that results in excellent sound quality and practically negligible thermal design limitations.
Infineon’s CoolGaN™ technology allows approaching the theoretical ideal performance of class D audio amplifiers due to its unique characteristics, perfectly suited for this application: zero reverse recovery charge (Qrr) of the body diode, linear input and output capacitances, and extremely fast switching speeds (lowest Qgd and Rg) result in ideal switching waveforms, close to an ideal switch. These ideal switching waveforms are the prerequisite to maximize audio performance and minimize power losses in class D audio amplifier.
Infineon’s CoolGaN™ 400V devices in PG-DSO-20-87 and PG-TOLL packages have been tested in class D audio amplifier applications on 300W + 300W dual-channel system designs.
For more information on class D audio reference designs please read Class D audio solution CoolGaN™ 400V e-mode HEMTs - Application Brochure
Saving operating and capital expenses, overall power supply footprint and highest solution robustness have been and will remain the major concerns in telecommunication infrastructure development. Infineon’s CoolGaN™ solutions address these challenges by providing benchmark efficiency in the entire operation range, maximizing power density and following Infineon’s stringent qualification regimen.
A 3.6kW Telecom SMPS system has been designed using CoolGaN™ 600V, 70mΩ (IGT60R070D1) devices. The system is based on LLC DC-DC topology with up to 400VDC input and 52.5V output voltage, delivering up to 3.6kW of power at 160W/inch3 power density. Peak efficiency of this system reaches 98.5% (Vin=390VDC, Vout=52.5V) and remains greater than 97% for loads higher than 20%.
Combining CoolGaN™ in the DC-DC stage with CoolGaN™ based PFC stages will maximize achievable power density and power conversion efficiency, and therefore reduce operating expenses for telecom suppliers. In addition, Infineon’s CoolGaN™ devices and technology have been fully qualified based on industrial requirements to ensure ultimate robustness when deployed in telecom SMPS.
The Internet of Things (IoT), big data, machine learning and artificial intelligence are driving the power demand for servers and data centers, posing new challenges to SMPS efficiency and form factors. Data center architects face the challenge to increase the delivered power in a given form factor and/or increase efficiency levels to reduce operating costs of server farms.
Both challenges can be addressed with Infineon’s CoolGaN™ technology: by implementing CoolGaN™ in a totem pole PFC combined with a LLC DC-DC stage, >98.5% system efficiency can be achieved (for 48V output voltage systems) providing a total of 2 billion kWh annual savings for US data centers (~ 300 million USD annual savings @ 0.15 USD / kWh). Additionally, GaN based SMPS solutions will enable a doubling of compute power per rack by pushing the power density to >80W/in3 from today’s typical ~30-40 W/in3 based silicon solutions.
The outstanding performance of Infineon CoolGaN™ is demonstrated in a full-bridge totem pole PFC efficiency graph reaching >99% peak efficiency. The system has been designed using CoolGaN™ 600V, 70mΩ devices in a PG-DSO-20 package (IGO60R070D1).
Charger and adapter
Travelling with multiple and often clunky chargers and adapters for phones, tablets and laptops has been a nuisance for many consumers and often leads to frustrations due to the additional weight and required space. Over the past years manufacturers of chargers and adapters became increasingly aware of these issues and a trend towards higher power density and consequently smaller devices has emerged. Today, the typical power topology used in such systems is a flyback power conversion topology and the form factor is limited by the efficiency achievable at 90VAC input voltage and full load. The highest power density systems available today reach ~12W/in3 (for 65W maximum output power).
Infineon CoolGaN™ enables a breakthrough with respect to power density for adapter and charger systems enabling ~20W/in3 power density systems (for 65W maximum output power). This advantage can be realized by implementing Infineon CoolGaN™ in a half-bridge topology that allows increasing switching frequency and efficiency simultaneously.
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