Hall electromotive force signal detection circuit having a difference calculation circuit and current sensor thereof

A hall electromotive force signal detection circuit, comprising:

• a hall element configured to generate a signal that includes a hall electromotive force signal and an offset signal component;
• a first switching circuit configured to modulate the hall electromotive force signal at a frequency of a chopper clock to generate an output voltage signal from the first switching circuit;
• a signal amplifier circuit configured to amplify the output voltage signal from the first switching circuit to output a first output signal having the hall electromotive force signal and the offset signal component, the offset signal component being modulated at the frequency of the chopper clock;
• and
• a feedback circuit configured to generate a feedback signal representing a ripple in the first output signal to the signal amplifier circuit,
• wherein the signal amplifier circuit comprises:
• a first transconductance element configured to convert the output voltage signal from the first switching circuit into a first current;
• a second switching circuit configured to demodulate the hall electromotive force signal based on a primary current 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 third switching circuit directly connected to the pair of the resistors and configured to invert a polarity of the divided voltage generated by the voltage-division based on the frequency of the chopper clock to generate an output voltage;
• and
• a second transconductance element configured to convert the output voltage from the second switching circuit into a second current, and configured to output the second current to the second switching circuit,
• wherein the feedback circuit comprises a third transconductance element configured to convert the feedback signal into a third current, and configured to output the third current to the second switching circuit, and
• wherein the primary current is a sum of the first current, the second current, and the third current.