[Column] What is Impedance? Differences from Resistance, Measurement Methods, and Precautions

What is impedance? Introducing the differences from resistance, measurement methods, and precautions! Leave circuit design and printed circuit board design and development to Nippo!

Impedance is a quantity that indicates "electrical resistance" in an electrical circuit. Unlike the resistance in direct current (DC) circuits, it serves as an important indicator of the relationship between voltage and current in alternating current (AC) circuits. Resistance has the characteristic of converting electrical energy into heat and indicates the ratio of voltage to current in DC circuits. On the other hand, impedance indicates the ratio of voltage to current in AC circuits and is a complex quantity that includes not only resistance but also reactance and inductance. ■ Measurement Methods and Precautions To measure impedance, specialized equipment such as an impedance analyzer or an LCR meter is used. By using these devices, you can accurately grasp the impedance characteristics and reactance components for each frequency. When measuring, it is important to be aware of the effects of parasitic inductance and capacitance. Especially at high frequencies, errors are likely to occur, so the arrangement of cables and shielding treatment becomes crucial. Additionally, if the calibration of the measuring instrument itself is insufficient, errors can be amplified, making regular adjustments and management essential for improving reliability. Our company provides comprehensive support from circuit design to printed circuit board implementation. Please feel free to contact us.

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