摘要
仪表放大器通常工作在噪声嘈杂的环境中,当输入放大器工作时,RF 干扰的 AC 共模电压可能产生 DC整流并由此引发仪表放大器输出工作点的漂移,导致大量共模噪声转化为差模噪声。使用一种平衡式多层陶瓷电容(MLCC)可以提高 CMRR(共模抑制比)和防止仪表放大器中的 DC 整流。
Instrumentation amplifiers are often employed in hostile noise environment. Sensor cables may pick up substantial RF radiation, particularly ,if they are long and/or not well shielded. When sensors are applied to the input of an instrumentation amplifier, AC common-mode voltages can result in DC rectification, and a consequential drift of the output operating point of the instrument amplifier, which is the reason that common-mode interference transform into differential-mode interference. This article compares a traditional solution with a new solution for RFI suppression using a balanced multi-layer ceramic capacitor （MLCC） to improve CMRR and prevent DC rectification in instrumentation amplifiers.
