Pico-current Measurement Challenges and Remedies: A Review

Abstract

A Pico-ammeter has versatile application in the measurement of low current of nuclear detector, biological cell or tissues and to know the character of new electronic devices. But noise can be generated due to some internal and external sources such as, poor design, placement of ammeter, dust, humidity, bending of connecting wires and even the selection of electronic devices, thus the measurement goes tricky. Several design techniques, guarding, shielding, and an unconventional wiring technique can help to measure low current accurately by reducing noise. This paper describes this low current measurement problems in detail and their corresponding solutions. It also shows the comparison of different low current measurement systems (LCMS). Feedback type ammeters are more preferable than shunt ammeter and current conveyor technique. In operational amplifier selection, CMOS type op-amp is better than BJT and FET.