Electronics: Question about input/output impedance

Simple -

1) Input impedance of a system should be high so that the system does not load the source.

2) Output impedance of a system should be low so that any load connected to this system does not receive a lower voltage because of a voltage drop across the system output impedance.

-Karthik
😁

thanks dude

High input impedance ensures that your circuit doesn't "load" the source that's driving it. If the input impedance is too low, it draws a lot of current from the previous stage or sensor, which can alter the voltage you're trying to measure and distort the signal. That's why oscilloscopes, amplifiers and other measurement devices are designed with megohm or even gigohm input impedance.

Low output impedance, on the other hand, lets your circuit deliver power to the next stage without significant voltage drop. A low source impedance means the output voltage stays relatively constant even when the load varies, which improves signal integrity and power transfer. Audio amplifiers, op‑amps and voltage regulators are designed with milliohm‑level output impedance for this reason.

So in general you want a high input impedance to avoid loading the source and a low output impedance to efficiently drive your load.

High input impedance ensures that your circuit doesn't "load" the source that's driving it. If the input impedance is too low, it draws a lot of current from the previous stage or sensor, which can alter the voltage you're trying to measure and distort the signal. That's why oscilloscopes, amplifiers and other measurement devices are designed with megohm or even gigohm input impedance.

Low output impedance, on the other hand, lets your circuit deliver power to the next stage without significant voltage drop. A low source impedance means the output voltage stays relatively constant even when the load varies, which improves signal integrity and power transfer. Audio amplifiers, op‑amps and voltage regulators are designed with milliohm‑level output impedance for this reason.

So in general you want a high input impedance to avoid loading the source and a low output impedance to efficiently drive your load.