Relation between Bandwidth and Rise time:
The frequency range from fL to fH is called bandwidth of the amplifier. Usually fL<<fH. So we can approximate the equation for bandwidth as follows,
The relation between rise time with upper frequency as,
So we can relate bandwidth with rise time as follows,
If the rise time of BJT is 35ns, what is the bandwidth that can be obtained using this BJT.
tr = 0.35 / f2 = 0.35 / BW
BW = 0.35 / tr = 0.35 / (35 * 10-9) = 10MHz