A Very Simple Low Noise Voltage PreamplifierFor High Sensitivity Noise Measurements

摘要

An ultra low noise voltage preamplifier is presented that, while characterized byexcellent noise performances, is based on a very simple topology. Indeed, the choice has beenmade of maintaining the component count to a minimum and of avoiding, by design, that anytrimming or calibration step be required. This was done in order to make the realization of thispiece of instrumentation as simple as possible for any researcher interested in noisemeasurements. The amplifier is AC coupled with a low corner frequency below 100 mHz and auseful bandwidth in the order of a few kHz. The voltage gain is 80dB and the equivalent inputvoltage noise is 14, 1.4 and less than 1 nV/iHz at 100 mHz, 1 Hz and for f>10 Hz, respectively.