Mosfet Current-to-Frequency Converter with a Linear Sub Picoampere-to-Microampere Range
Edward G. Shapiro · IEEE Transactions on Nuclear Science · 1971
A current-to-frequency converter with a single linear current range of 10-13 to 106 amperes has been developed for monitoring ion chamber currents. The converter has an output transfer function of 10-11 amperes/ Hz or 10-11 coulombs/count which is temperature compensated. Its frequency output, which is compatible with most scalers, yields a maximum linear rate of 105 Hz at 10-6 amperes input current.