
306 Optical Fiber Communication Systems with MATLAB
®
and Simulink
®
Models
1mA is produced and fed into the differential TIA. This in turn produces a differential volt-
age
of 4–5 V signals at the output. Unfortunately, this level will saturate the outputs of the
DTIA. So, normally an automatic gain control stage is employed to increase the dynamic
range of the optical receiver. The parameters of differential TIA with the input-referred
current noise of the InP TIA are approximately
pA/ Hz
on average to a bandwidth of
40 GHz.
It
is noted that one of the main problems with DTIA is the high transimpedance gain
that would lead to the saturation ...