What is the significance of having a signal generator with a

What is the significance of having a signal generator with a high output impedance.

Solution

It helps in impedance matching. Output impedance is a measure of the driving capability of a signal source. The output impedance of a source may be matched to the input impedance of the circuit that it is driving.

If the output signal is current, its value will not change a lot with load. Desirable property for a current source(e.g - output of a current mirror). Cascading a current mirror improves its output impedance a lot.

The lower the input impedance and higher the output impedance, the less strain on the source to supply high current and the lower the loss of signal and noise.

The signal generator output is only correct when it is terminated properly. For example. if the function generator is used to provide a test signal at the input to a circuit with a high input impedance then it is necessary to use a terminating resistor at the input of the circuit under test to avoid a severe impedance mismatch. An impedance mismatch will distort the test signal and make the test invalid and worthless.So that we can terminate the output of the function generator into the same impedance as the output impedance of the function generator