Abstract: A magnetic field sensing device is provided. The magnetic field sensing device includes a magnetoresistance sensor, a Hall sensor, and a calculating circuit. The magnetoresistance sensor senses a magnetic field to provide a magnetoresistance sensing value. The Hall sensor senses the magnetic field to provide a Hall sensing value. The calculating circuit provides a weight value according to the magnetoresistance sensing value, generates a first calculating value according to the weight value and the Hall sensing value, and generates a second calculating value according to the weight value and the magnetoresistance sensing value. The calculating circuit calculates on the first calculating value, the second calculating value, and the magnetoresistance sensing value to generate an output signal with an output value. The output value is associated with a strength of the magnetic field.

Abstract: A leakage current detection circuit and a fluxgate driver are provided. The leakage current detection circuit is suitable for a fluxgate device. The leakage current detection includes a duty cycle detection circuit, a compensation circuit, and a control signal generation circuit. The duty cycle detection circuit receives a pulse width modulation (PWM) signal from an inverter circuit. The duty cycle detection circuit detects a duty cycle of the PWM signal by sampling the PWM signal with a clock signal to output a count signal. The compensation circuit adjusts a pulse number of the count signal according to an offset signal in a self-test period. The control signal generation circuit calculates an average value of the count signal, and compares the average value with multiple threshold values to respectively generate multiple control signals. The control signals indicate a leakage current state of the fluxgate device.

Abstract: A magnetic sensor is disclosed. The magnetic sensor includes a first magnetic sensing device, a second magnetic sensing device and a third magnetic sensing device. The first magnetic sensing device and the second magnetic sensing device sense X-axis and Y-axis magnetic fields. The third magnetic sensing device is a Hall device to sense Z-axis magnetic field by Hall effect. The first magnetic sensing device is disposed in a 90 degrees position related to the second magnetic sensing device.