Experimental characterization of bandwidth limits in hall sensors

Modern power applications are demanding for broadband current sensors. Hall sensors are a good solution from a general standpoint, but practical implementations are limited to a few hundred kHz. In fact, many parasitic dynamic effects perturb the time response of the Hall sensor, making difficult to experimentally assess the fundamental frequency limit and achieve it in the applications. This paper presents an equivalent electrical model that helps to design a test aimed at experimentally estimating the intrinsic time response of the sensor. According this test, the paper demonstrates that Hall sensors have an upper bandwidth limit defined by the overall capacitive load. Moreover, some of the parasitic dynamic effects, which degrade the time response in real operation, are identified and investigated.