Technology: imec GaN-IC 650V
Niklas Deneke, Tim Rambousky
Improving offline power conversion
The target application field is offline power conversion, i.e., bridgeless power factor correction (PFC) for home appliances and lighting in the 200W power range, which accounts for 60% of the EU residential power consumption [1].
Layout of the 400V, 1MHz PFC GaN converter
Designing the high-efficiency GaN converter
The design includes a fully integrated 650V GaN half-bridge power stage applicable for totem-pole PFC. The IC comprises high-voltage power transistors, gate drivers with short propagation delay, a fast and power-loss optimized level shifter with >200V/ns CMTI suitable for 400V operation and a supply regulator for self-biased offline operation based on previous design experience of the research group [2], [3].
Simulated GaN half-bridge switching behavior (switching output node Vsw).
The target power level of the demonstrator is at 200W with a power efficiency greater than 99%. Without the availability of low-forward-voltage diodes and complementary devices, innovative protection and clamping circuits are designed to ensure safe operation during switching transitions with slew rates as high as 200V/ns.
High-side and low-side power HEMT gate voltages VG,HS and VG,LS referenced to the respective ground.
Reducing global power consumption
Enhancing the conversion efficiency contributes significantly to reducing global power consumption and related greenhouse gas emission. High switching frequencies supported by GaN enable small passives and more compact solutions while saving valuable resources.
Acknowledgements
Thanks to imec’s GaN-IC MPW team, especially to Maritza T. Ortiz, for supporting on a variety of aspects during the design phase of the IC.
References
[1] https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Energy_consumption_in_ households
[2] M. Kaufmann and B. Wicht: A Monolithic GaN-IC with Integrated Control Loop for 400V Offline Buck Operation Achieving 95.6% Peak Efficiency. In IEEE Journal of Solid-State Circuits, vol. 55, pp. 3169 – 3178, December 2020
[3] M. Kaufmann, M. Lueders, C. Kaya, B. Wicht: A Monolithic E-Mode GaN 15W 400V Offline SelfSupplied Hysteretic Buck Converter with 95.6% Efficiency. 2020 IEEE International Solid- State Circuits Conference – (ISSCC), San Francisco, CA, USA, 2020, pp. 288-290
