Design method for improving detection accuracy of current of precision resistor

Abstract

The invention discloses a design method for improving the detection accuracy of the current of a precision resistor. According to the design method, two welding pins of the precision resistor which are located on a PCB are segmented into four welding pins, wherein two of the welding pins are used for carrying current on a closed circuit, and the other two welding pins are used for wiring feedback wires. The detection accuracy of the precision resistor is improved from the perspective of layout, the characteristics or parameters of the precision resistor are not required to be changed, and therefore, the design method can be imported very easily based on an existing design scheme, and existing design lines will not be impacted at all; the detection accuracy of the precision resistor can be improved, accuracy error can be controlled in a very small range, welding impedance can be reduced fundamentally, and impedance accuracy can be improved; and the feedback wires at two ends of the precision resistor adopt a Kelvin wiring mode, and therefore, differential mode interference can be reduced, and detection accuracy can be improved.

Description

Technical field [0001] The invention relates to the technical field of voltage detection, in particular to a design method for improving the precision of precision resistance current detection. Background technique [0002] In the current hardware circuit design work, to realize a certain detection function, a precision resistor is usually used to detect the current or voltage value in the circuit. In actual use, the precision resistor will feed back the detected voltage value to a data processing chip through the feedback traces at both ends. The data processing chip uses Ohm’s law to calculate the current value flowing through the precision resistor to achieve this detection. Test function. [0003] Generally, in pursuit of higher detection accuracy, R&D engineers will continue to improve the accuracy of the precision resistors used, and the increase in precision resistance often leads to a double increase in the cost. The cost of precision resistance with an accuracy of 0.1% is...

AI Technical Summary

Problems solved by technology

Although the feedback wiring adopts the Kelvin wiring method, the two feedback wirings are pulled out from the inner side of the pin

The impedance of the precision resistor actually used only includes the impedance of the middle part, and does not include the impedance of the entire precision resistor. The current value calculated by the data processing chip through Ohm's law is smaller than the actual working current value, and the detection error A larger value cannot reflect the real working current; since the resistance value of precision resistors is often extremely low, a small welding resistance will also have a greater impact

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