TWO-WIRE, DIGITAL HALL-EFFECT SENSORS OFFER SYSTEM SIMPLICITY, NOISE-FREE OPERATION, and RELIABLE REMOTE SENSING CAPABILITY

摘要

Typically, Hall-effect sensor ICs entail three (or more) circuit connections to provide magnetic sensing functions. However, some of the newest digital Hall-effect devices (HEDs) can nowadays offer noise-free signals and two-wire operation despite very lengthy interconnection systems. The new two-wire, Hall-effect sensors function with 'current-mode' signals (vs. voltage-mode); thus, they are (fundamentally) unaffected by ambient, random noise (or other systems transients) which degrade 'voltage-mode' signal integrity in severe, noisy environments. Such two-wire, contactless, stable magnetic sensors operate from unregulated, or poorly regulated, power sources ranging from 3.5 V to 24 V, without corrupting either function or performance of these digital, magnetic sensing functions exploiting 'current-mode' signals. These two-wire 'chopper-stabilized' magnetic sensors afford the benefits of better temperature stability and higher sensitivity when compared to earlier HEDs lacking the dynamic quadrature dc offset cancellation circuitry (now usually termed 'chopper-stabilization'). Further these innovative HEDs mirror recent trends toward 'applications-focused' magnetic sensing, and are more properly termed Hall-effect transducers.