Fully-integrated current sensor chip with TMR and ASIC

Abstract

The invention discloses a fully-integrated current sensor chip with TMR and ASIC. The fully-integrated current sensor chip comprises a TMR magnetic resistance bridge, a magnetism gathering layer, an ASIC chip, a lead frame, bonding leads and an encapsulation body, wherein the TMR magnetic resistance bridge is composed of at least one magnetic resistance bridge arm; each magnetic resistance bridgeis composed of a magnetic resistance structure or is composed of plurality of magnetic resistance junctions which are connected in series; each magnetic resistance junction comprises a bottom electrode layer, a seed layer, a pinning layer, a pinned layer, an isolation layer, a free layer, an offset layer, a protection layer and a top electrode layer; the magnetism gathering layer is used for enabling a sensitive direction of a TMR magnetic resistor to be vertical to the surface of the fully-integrated current sensor chip with TMR and ASIC; the ASIC chip and the TMR magnetic resistance bridge are located in the encapsulation body. According to the fully-integrated current sensor chip with TMR and ASIC, the TMR sensor and the ASIC are encapsulated in an independent encapsulation body, so that peripheral components of the current sensor chip are reduced to a maximum limit; the design difficulty of the system can be reduced; the assembling efficiency can be improved.

Description

technical field [0001] The invention relates to the field of magnetic sensors, in particular to a TMR and ASIC fully integrated current sensor chip. Background technique [0002] At present, most of the current detection on the market uses current transformers. This technology is relatively mature, but its shortcomings are also very obvious: because it is based on Ampere's law and the law of electromagnetic induction, it can only measure AC signals; the introduction of inductance brings the hysteresis effect of the system. , resulting in a large angle difference; the magnetic core is a nonlinear component, and the current transformer has a relatively large difference between high and low currents; when the current is large, the magnetic core is easily saturated, resulting in measurement failure. [0003] Magnetic sensors, as devices for detecting magnetic fields, are increasingly being used in the field of current detection. Around the wire, there is a magnetic field gene...

AI Technical Summary

Problems solved by technology

However, the natural disadvantage of the Hall sensor is its poor temperature characteristics. At high temperature and low temperature, the sensitivity difference is huge, which makes the Hall current sensor unable to work in applications with a wide temperature range.

However, the manufacturing cost of the fluxgate is high, and its signal processing circuit is relatively complicated, and the overall cost is high, which restricts its development.

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