Rise time and its Relation to Upper Cut-off Frequency:
Upper 3 dB Frequency:
step input is applied, amplifier high frequency RC network prevent the output
from responding immediately to the step input. The output voltage starts from
zero and rises towards the steady state value V, with a time constant R2C2
as shown in the above figure.
The output voltage is given by,
The time required for Vo to reach one-tenth of its final value is calculated as,
The difference between these two values is called as rise time tr of the circuit. The rise time is given as
The Upper 3dB frequency is given as,
Upper 3dB frequency in terms of rise time is given as,
From above equation, it shows that upper 3dB frequency is inversely proportional to the rise time tr.