Device with position detection

A device with position detection, comprising:

• a first hall element;
• a second hall element;
• a differential amplifier configured to apply an amplification gain to a first hall voltage generated by the first hall element and a second hall voltage generated by the second hall element to generate a subtraction voltage;
• a summing amplifier configured to apply the amplification gain to the first and second hall voltages to generate a sum voltage;
• a comparer configured to compare a reference voltage with the subtraction voltage to generate an error voltage;
• and
• a current converter configured to apply a voltage-current conversion gain to the error voltage to generate a bias current provided to the first and second hall elements based on the error voltage,
• wherein the voltage-current conversion gain and the amplification gain are determined based on a magnetic field of the first hall element and a magnetic field of the second hall element.

A camera module, comprising:

• a lens barrel;
• an aperture module coupled to the lens barrel and comprising an aperture configured to control an amount of light incident to the lens barrel;
• a coil;
• a magnet configured to move together with either one of the lens barrel and a component setting an opening size of the aperture;
• a driver configured to configured to apply a driving signal to the coil to cause the magnet to move based on electromagnetic interaction between the coil and the magnet;
• and
• a position detecting device comprising:
• a first hall element;
• a second hall element;
• a differential amplifier configured to generate a subtraction voltage by applying an amplification gain to differentially amplify a first hall voltage generated by the first hall element and a second hall voltage generated by the second hall element;
• a summing amplifier configured to generate a sum voltage by applying the amplification gain to summatively amplify the first and second hall voltages;
• a comparer configured to compare a reference voltage with the subtraction voltage to generate an error voltage;
• and
• a current converter configured to generate a bias current provided to the first and second hall elements, by applying a voltage-conversion gain to the error voltage,
• wherein the voltage-current conversion gain and the amplification gain are determined based on a magnetic field of the first hall element and a magnetic field of the second hall element, and
• wherein the position detecting device is configured to detect a position of the magnet based on the sum voltage.