- Definition
- Gallium nitride (GaN) is a wide-bandgap semiconductor material used in place of silicon in power conversion circuits, allowing higher switching frequencies and therefore smaller magnetic components and higher power density.
This page defines the term. For what it means in practice, see GaN chargers: what changes, and what does not.
What it changes
A switching power supply converts mains electricity by switching a transistor on and off tens or hundreds of thousands of times a second. Silicon transistors lose energy each time they switch, and the losses rise with frequency. That loss sets a practical ceiling on how fast the circuit can run.
Gallium nitride has a wider bandgap than silicon. It switches faster with lower losses, and it tolerates higher temperatures. Because the switching frequency can be raised, the transformers and inductors that dominate the size of a charger can be made smaller for the same power.
The result is the product category the market calls a GaN charger: the same wattage in a substantially smaller body, or more wattage in the same body.
What it is not
GaN is not a standard, a certification or a guarantee of quality. There is no GaN mark and no GaN certification scheme. It is a material choice, and the quality of a charger depends on how the whole circuit around it was designed.
A product described as a GaN charger tells you which semiconductor it uses. It does not tell you how the thermal path was designed, how the converter behaves at the edges of its range, or how long it will last. Those are the questions worth asking.