Electronic – loading effect


I have come across this term many times while studying amplifiers. How does this effect affect an amplifier circuit(or any other circuit in which it plays a role) and why is the input impedance kept as high as possible to negate it?

Best Answer

Loading refers to how your measurement circuit affects the attached device. If e.g. you want to read a sensor that has a big internal resistance Ro any current drawn will create you additional voltage error equal to io*Ro. Drawing as little current as possible lowers the sensor loading thus providing more accurate readout.