Circuit device for detecting magnetic field, has logic unit directing magnetization direction of RC oscillator at specified angle with respect to magnetization direction of another RC oscillator

摘要

The device has two RC oscillators comprising respective series capacitors (C1, C2) and respective series-connected magnetic field-dependent resistors (RG1, RG2). Nodes between the capacitors and the resistors are excited together with reciprocating oscillations during oscillation periods, respectively. Numerators (TDC-1, TDC-2) detect time durations of predetermined numbers of the oscillations. A logic unit (LU) evaluates the time durations and directs magnetization direction of one of the oscillators at an angle of 180 degrees with respect to magnetization direction of another oscillator. The magnetic-field-dependent resistors are designed as a colossal magnetoresistance (CMR) sensor, a tunneling magnetoresistance (TMR) sensor or giant magnetoresistance (GMR) sensor. An independent claim is also included for a method for determining magnetic field strength.