Camshaft position sensor circuit structure based on GMR chip

Abstract

The invention discloses a camshaft position sensor circuit structure based on a GMR chip. The camshaft position sensor circuit structure comprises a GMR power supply module, an analog circuit power supply module and a digital circuit power supply module which are connected to a power line, a difference GMR induction module is connected to the output end of the GMR power supply module, an operational amplifier circuit, a temperature sensor and two analog-digital conversion circuits are connected to the output end of the analog circuit power supply module, the output end of the digital circuit power supply module is connected with a digital signal processing module, the output end of the difference GMR induction module is connected to the digital signal processing module through the operational amplifier circuit and one of the analog-digital conversion circuits, the output end of the temperature sensor is connected to the digital signal processing module through the other analog-digitalconversion circuit, the output end of the digital signal processing module is connected with an output line through an OD output circuit, the input end of a crystal oscillator circuit is connected tothe digital signal processing module, and the digital signal processing module is further connected with the operational amplifier circuit. The anti-jamming capability of a camshaft position sensor toan outside electromagnetic field is high.

Description

technical field [0001] The present invention relates to the technical field of electronic information, and more specifically relates to a circuit structure of a camshaft position sensor based on a GMR chip. Background technique [0002] The TPO (True Power ON) function is to identify the relative position of the camshaft and the sensor (the sensor is facing the tooth or groove of the wheel) at the moment when the car is powered on, and the camshaft does not rotate. This function is mainly used with the start-stop function on the engine. At present, the camshaft position sensor with TPO function in the engine is based on the principle of the Hall effect and is designed with a single Hall chip. However, the Hall chip has poor resistance to external electromagnetic field interference, resulting in unstable output signals. The recognition accuracy is low. Contents of the invention [0003] The object of the present invention is to provide a camshaft position sensor circuit s...

AI Technical Summary

Problems solved by technology

At present, the camshaft position sensor with TPO function in the engine is based on the principle of the Hall effect and is designed with a single Hall chip. However, the Hall chip has poor resistance to external electromagnetic field interference, resulting in unstable output signals. The recognition accuracy is low

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