How to build Picoammeter circuit with 4 ranges

Circuit diagram

This circuit uses a CA3420 BiMOS op amp to form a picoammeter with 4 ranges. The exceptionally low input current (typically 0.2pA) makes the CA3420 highly suited for use in a picoammeter circuit. Input transient protection is provided by the 1 megohm resistor in series with the input. The 10 megohm resistor connected to pin 2 decouples the potentially high input capacitance often associated with lower current circuits and reduces the tendency for the circuit to oscillate under these conditions. The 10k potentiometer is used for null offset.

Author: Harris Semiconductor

Similar diagrams

We are not responsible for any injuries or damage caused by information from this website! Working with electricity is dangerous for your life, especially diagrams related to high voltage! We do not guarantee success in building devices using our diagrams! They are not tested by us. For questions about diagrams use author info below diagram or our contact page. Thank you!