Vertical sensitive magnetic sensor closed-loop on-chip in-place feedback device

Abstract

The invention discloses a vertical sensitive magnetic sensor closed-loop on-chip in-place feedback device, comprising a silicon-based substrate, a flux guider, four identical magnetoresistors, a signal feedback coil, an operational amplifier and a power amplifier, since a on-chip in-place feedback coil is disposed on a push-pull type vertical sensitive magnetic sensor chip, when feedback current is supplied, magnetic field signals having the same magnitude and opposite directions are generated in a sensitive axis direction of two pairs of magnetoresistors above the feedback coil to respectively counter the original signal magnetic fields and to form a closed-loop feedback structure, and the design of the on-chip in-place feedback device can effectively improve the sensor output linearity,improve the measurement accuracy and reduce the power consumption, thereby having an important application value.

Description

technical field [0001] The invention belongs to the technical field of magnetic sensors, and relates to a closed-loop on-core presence feedback device for a vertically sensitive magnetic sensor. Background technique [0002] With the rapid development of the field of magnetic sensors, their applications are becoming more and more extensive. The current vertical magnetic sensors are widely used in consumer electronics such as mobile phones and electronic compass mobile devices. Such products require smaller package sizes and higher Measure stability. [0003] Most of the existing vertically sensitive magnetic sensors are Z-axis package design, and the Z-axis package is to package the sensitive axis of the sensor chip on the vertical and horizontal plane, such as patent CN 102426344 A, which is an invention patent of a three-axis magnetic field sensor. A method of packaging and integrating three sensors is adopted, in which the sensor of the Z axis is placed on a vertical pla...

AI Technical Summary

Problems solved by technology

This method makes the sensor bulky, the packaging cost is high, the process is complicated, the stability is low, and the packaging is easy to break, etc.

Although there are single-core integrated vertically sensitive magnetic sensors, they are currently open-loop designs. For example, the name of the application number 201820341886.X is a push-pull vertically sensitive magnetic sensor, which uses a flux guide The Z-axis magnetic field of the Z-axis is converted into the leakage magnetic field component in the plane, and the magnetic field detection in the vertical direction is realized. However, in the case of measuring a large magnetic field, the magneto-sensitive resistor is easy to magnetic saturation and the hysteresis is large during measurement, which is very difficult. To a large extent, it affects the measurement bandwidth, measurement accuracy and linearity of the sensor, and the open-loop design has poor linearity and low measurement accuracy, which is difficult to meet the needs of modern industries

The design with feedback can use the feedback system itself to correct the sensor measurement error, but there is no case of on-core on-position feedback design for vertical magnetic sensor chips at present, so a closed-loop on-core on-position feedback vertical sensitive magnetic sensor is urgently needed solve the above problems

Images