GaN Systems Inc of Ottawa, Ontario, Canada, a fabless producer of gallium nitride (GaN)-based power switching semiconductors for power conversion and control applications, has released a new Application Note for design engineers that sets out thermal design guidelines and PCB layout choices for its enhancement-mode (E-mode) power switching transistors, which are supplied in its proprietary GaNPX device packaging.
These are reckoned to be the first discrete power devices to be embedded in a laminate construction - conventional packaging techniques (such as clips, wire bonds and moulding compounds) have been replaced with galvanic processes. These design features of GaNPX packaging significantly increase the current-carrying capability of GaN Systems’ devices and reduce the critical loop inductance, making driving the high-speed, high-current switches far easier, it is claimed.
The Application Note gives a thermal analysis of GaN Systems’ GS66508P E-mode GaN, 34A, 41mΩ power switch, together with diagrams showing its thermal dissipation paths and further explanation of how heat is dissipated by the GaNPX packaging design.
The second part of the Application Note looks at the key PCB factors to consider when designing with GaNPX devices: the heat-spreading copper pad and the design of the thermal vias.
The third section contains a thermal analysis of three different PCB layouts with different copper layers and thicknesses and looks at details of the optimum layout.
Lastly, there is a section looking at how designers can utilize the maximum power capability of GaN Systems’ devices and estimate the maximum power capacity of the system they are designing.
