Manufacturing method for current sensor and current sensor
View Patent ↗A manufacturing method is used for a current sensor including a current measurement circuit configured to include magnetoelectric conversion elements, a first amplification-and-correction circuit configured to amplify an output of the current measurement circuit and correct, based on a set first correction amount, a temperature characteristic of an offset, a second amplification-and-correction circuit configured to amplify an output of the first amplification-and-correction circuit, adjust a sensitivity, and correct, based on a set second correction amount, a magnitude of the offset, and a substrate in which the current measurement circuit, the first amplification-and-correction circuit, and the second amplification-and-correction circuit are provided, wherein after the first correction amount is set based on characteristics of the magnetoelectric conversion elements, the magnetoelectric conversion elements are mounted in the substrate and the second correction amount is set.
1. A method for manufacturing a current sensor including a current measurement circuit including magnetoelectric conversion elements, a first amplification-and-correction circuit configured to amplify an output of the current measurement circuit and correct, based on a first correction amount, a temperature characteristic of an offset, a second amplification-and-correction circuit configured to amplify an output of the first amplification-and-correction circuit so as to adjust a sensitivity, and correct, based on a second correction amount, a magnitude of the offset, and a substrate on which the current measurement circuit, the first amplification-and-correction circuit, and the second amplification-and-correction circuit are provided, the method comprising:
setting the first correction amount based on characteristics of a sample magnetoelectric conversion element taken from a same lot or wafer from which the magnetoelectric conversion elements are obtained;
mounting the magnetoelectric conversion elements on the substrate after the setting the first correction amount; and
setting the second correction amount after the mounting.
2. The method for manufacturing a current sensor according to claim 1 , wherein the first correction amount is set so as to reduce temperature dependency of the offset.
3. The method for manufacturing a current sensor according to claim 1 , wherein each of the magnetoelectric conversion elements is a magnetoresistance effect element.
4. The method for manufacturing a current sensor according to claim 1 , wherein the current sensor is a magnetic proportional type sensor utilizing the output of the current measurement circuit proportional to an external magnetic field.
5. The method for manufacturing a current sensor according to claim 1 , wherein the current sensor is a differential type sensor including another set of the current measurement circuit and the first amplification-and-correction circuit, the second amplification-and-correction circuit performing a differential operation on outputs of the current measurement circuits.