Measuring the signals from extremely high-impedance sensors is a difficult task. Such sensors can have output impedances in the teraohms (TΩ). The tiny signal currents coming from sensors like Faraday cups and photodiodes require electrometer-grade amplifiers for measurement. Amplifiers of this type can resolve currents as small as 1 femtoampere (fA) when configured as a transimpedance amplifier (TIA)...
Register or Sign in below to download the full article in .PDF format, including high-resolution graphics and schematics when applicable.