Patent ID: 11946987
Assignee: ASAHI KASEI MICRODEVICES CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A signal detection circuit, comprising:
a magnetic sensor element configured to generate a signal that includes a magnetic signal and an offset signal component;
a signal amplifier circuit configured to amplify the signal generated by the magnetic sensor and configured to output a first output signal having the magnetic signal and the offset signal component; and
a feedback circuit configured to generate a feedback signal indicating a ripple component based on the offset signal component in the first output signal by performing time derivative of the first output signal, and configured to output the generated feedback signal to the signal amplifier circuit,
wherein the signal amplifier circuit comprises:
a first switching circuit configured to demodulate the signal generated by the magnetic sensor based on a primary current and configured to generate the first output signal;
a pair of resistors connected in series and configured to perform voltage-division on a component included in the first output signal at a predetermined ratio to generate a divided voltage;
a second switching circuit directly connected to the pair of the resistors and configured to generate an output voltage; and
a transconductance element configured to convert the output voltage from the second switching circuit into a current and configured to output the current to the first switching circuit by adding the current to the primary current.