Understanding the limits of a hall sensor sensitivity for integration on a GaN power transistor chip: experiments with market available components

Gallium Nitride (GaN) is an emerging wide bandgap technology in power electronics. It enables higher power density, wider operating temperature range and higher efficiency compared to other widely used technologies, allowing miniaturization and overall weight and cost reductions at system level. In contrast, the technology produces high levels of radio emissions and it is prone to failure without an adequate active power monitoring due to its sensitivity to unmatched electrical parameters. Since intrusive monitoring can disrupt the transistor's efficiency on power delivery, galvanic isolated sensors are intensely explored with the goal of chip-level integration on the difficult-to-manufacture GaN structures. The experimental results in this study reveal that in a power monitoring scenario envisaged for the integration on a GaN transistor chip, a Hall sensor that requires a minimum magnetic field threshold of 1 mT will be sufficient. The noisy GaN transistor environment is tested for three different low power loads, resistive, semi-conductive, and inductive, at 1, 5 and 10 kHz, demonstrating that the radiated emissions relate to the load current rather than voltage, whereas the Hall device measurements show stability and consistency.