The HXR45100 is an extension of the low-power, single-ended input, single-channel linear Trans-Impedance Amplifier (TIA) of HXR44100, and a member of the Optical Receiver Transmitter Array (ORTA) product family. Together with a PIN detector, the HXR45100 can be used to design a compact linear Receiver Optical Sub-Assembly (ROSA) for the next-generation 400G optical transceivers with advanced modulation schemes in 53Gbaud PAM4 data rates. This TIA operates in a 3.3V supply or a 2.9V supply for low power consumption, providing exceptionally low input referred noise density, wide input optical power range, excellent linearity up to 3mA overload, and a high bandwidth. The chip is designed with the patented adaptive biasing scheme.