Avalanche and overvoltage
Superjunction has junction with avalanche capability
– Useful in circuits with unclamped inductive energy (flyback)
GaN has no junction, no avalanche behavior
– GaN ultimately breaks down destructively at ~2x rating
– Overvoltage spikes are allowed depending on supplier
GaN is best suited for half-bridge topology
– Fast body diode helps to mitigate overvoltage spikes
– Overvoltage spikes are clamped to bus
– With proper design, no risk of breakdown
APEC 2015 Seminar S17
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