Bandwidth Limits in Hall Effect-based Current Sensors
Modern power applications are demanding for small and broadband current sensors. Hall sensors are a good solution, but practical implementations are limited to a few hundred kHz. The literature offers a theoretical knowledge about the dynamic effects acting on the Hall probe but does neither define nor experimentally assess the bandwidth fundamental upper limit, since many parasitic dynamic effects perturb the inherent time response of the Hall sensor. This paper experimentally investigates the bandwidth upper limits in CMOS Hall effect-based current sensors. Based on the physics-based description of the Hall probe, the paper defines a novel, special-purpose, measurement technique, which is able to experimentally evaluate the inherent response time of the Hall probe without triggering the main parasitic effects. The paper also propose an equivalent electrical model describing the dynamic response of the Hall probe so as to better explain and understood the measurement results. Specifically, the paper identifies two bandwidth upper limits: a fundamental limit set by the intrinsic capacitance, which models the transversal charge accumulation due to the Hall effect, and a more practical limit set by the capacitive input of the electronic readout interface. Some main parasitic effects are then assess and added in the proposed model.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).