The SY88053AL, limiting post amplifier is designed for use in fiber-optic receivers for applications up to 12.5Gbps. It features a decision threshold control that can be used for offset compensation or to optimize the Bit Error Rate (BER) in noisy applications as WDM where optical amplifiers such as EDFAs and Raman amplifier are used. This device connects to typical transimpedance amplifiers (TIAs). The signal from TIAs can contain significant amounts of noise unevenly distributed between its top and bottom rails due to the Amplified Spontaneous Emission (ASE) noise generated by the optical amplifiers. In order to optimize the BER in such noisy conditions, the decision threshold between bit 1 and bit 0 needs to be moved to the rail that contains less noise. An external voltage applied at the VTHP pin on the SY88053AL will move the crossing point up and down, from 20% to 80%, to achieve the best BER.