This paper presents the X-Hall sensor, a viable sensing architecture for implementing a silicon-integrated, broadband, current/magnetic sensor. The X-Hall sensor overcomes the bandwidth limit of the state-of-the-art Hall sensors by replacing the spinning-current technique with DC-biased-based, passive offset compensation. In this way, the X-Hall architecture removes the methodological bandwidth limit due to the spinning-current technique and allows for exploiting the Hall probe up to its practical limit, which is set by the parasitic capacitive effects. Moreover, the X-Hall architecture allows to push the practical bandwidth limit at higher frequencies due to both the removal of the switches inherent in the spinning-current approach and a specifically designed analog front-end. To this end, a differential-difference current-feedback amplifier (DDCFA) is proposed as analog front-end in the X-Hall sensor. A prototype of the proposed X-Hall architecture is implemented in BCD 0.16-μm silicon technology to experimentally assess the performance of the X-Hall architecture. The passive offset compensation implemented into the X-Hall architecture is frequency independent and preserves an adequate offset reduction performance, though less efficient than the spinning-current technique operated at low frequency. Experimental dynamic tests on the prototype identify the presence of an additive parasitic dynamic perturbation due to the package that prevents from fully exploiting the X-Hall prototype up to its designed bandwidth limit. However, the implementation of a post de-emphasis digital filter allows to mitigate for the dynamic perturbation and to experimentally achieve a sensor bandwidth of 4 MHz, which is the broadest bandwidth ever demonstrated by a purely Hall-effect based sensor.

Power electronic circuits are moving towards higher switching frequencies, exploiting the capabilities of novel devices, so as to shrink the dimension of the passive components. This trend demands sensors able to operate at such high frequencies. This article aims to demonstrate the broadband capability of a fully integrated CMOS current sensor based on the X-Hall approach and configured in current mode, by alleviating the impact of stray capacitive loading at the probereadout interface. Current-mode operation enables the usage of a transimpedance amplifier as readout circuit, offering better bandwidth, noise and power performance than conventional instrumentation amplifiers. The system exploits a common-mode control system to operate the sub-modules at different supply voltages, respectively 5 V for the X-Hall probe to achieve high sensitivity, and 1.2 V for the readout to exploit the high transition frequency of transistors with reduced oxide thickness. A chip-on-board mounting limits the parasitic inductive effects on the host PCB. The developed prototype achieves a maximum acquisition bandwidth of 12 MHz. With a power consumption of 11.46 mW and a resolution of 39 mA _rms , it presents a sensitivity of 8% T ^-1 and achieves a FoM of 569 MHz/A ² mW, which is significantly higher than current state-of-the-art hybrid Hall/coil solutions. The prototype is implemented in a 90-nm microelectronic process from STMicroelectronics and occupies a silicon area of 2.4 mm ² .

We propose a circuit arrangement that exploits the sense coil of a planar PCB fluxgate to generate the compensation static field in the closed loop configuration. This approach allows to overcome the difficulties related to the optimization of the coupling efficiency between compensation and sense coil. Experimental results are presented to demonstrate the feasibility of the proposed approach.

GaN power transistors are being increasingly used in high-power and high-frequency electronic systems due to their high breakdown field, high carrier density, and good thermal conductivity. Despite these advantages, system durability of GaN-based power systems is hindered by the necessity to work at variable operating conditions. The necessary real-time monitoring of the load current is normally implemented by using external shunt resistors, yet the implementation of GaN-based isolated current sensor would be beneficial to the final power system in terms of space occupation as well as cost. This work describes the implementation of two Hall-effect devices in p-GaN technology, which can potentially be used as integrated current sensors in GaN monolithic implementation. These devices are experimentally characterized and compared in terms of sensitivity, offset, and input resistance. Some non-ideality effects are also outlined, identifying future research directions.