摘要
A fully integrated CMOS active probe for characterizing conducted electromagnetic interference (EMI) in the gigahertz range is presented. Based on the direct coupling method of International Electrotechnical Commission standard, the active 1Ω current probe is designed and realized by a standard 0.18μm CMOS technology to overcome a large insertion loss of 34.2 dB in the conventional passive probe. A high-precision on-chip 1Ω resistance is implemented at the input, followed by a high gain and wideband amplifier in the proposed EMI probe. The measured insertion loss is significantly reduced to ∼ 18 dB with a bandwidth up to 3 GHz. Also, the conducted emission of a microcontroller unit is tested, which demonstrates that the proposed active probe could capture very low-level high-frequency interference overlooked by the conventional passive probe.