Weak current with the magnitude of μA

p

A is usually measured in semiconductor testing

and measuring methods may include several possible current meter connecting ways.A kind of weak current measuring module is developed for adapting the current measurement range and the flexibilities of connections.The module is designed based on a low bias current transimpedance amplifier.A microcontroller in the module is used for A/D converting and auto range selection.Signal and power supply isolation is designed for variable connections.Several special steps are taken for improving the precision and protecting the module.10pA resolution and 0.1 % INL have been finally realized for the requirement of the target semiconductor testing device.The weak current measuring module coul

d also be used in other fields such as photoelectric measurement and nuclear electronics measurement.