The SY88353BL limiting post amplifier is designed for use in fiber-optic receivers, and is specially optimized for WDM applications where optical amplifiers such as EDFAs and Raman amplifier are used. The device connects to typical transimpedance amplifiers (TIAs). The linear signal from TIAs can contain significant amounts of noise that is unevenly distributed between top and bottom rails due to the ASE noise generated by the optical amplifiers, crosstalk, or non-linear effect in the fiber. 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. The SY88353BL features a pin at which an external voltage can be applied to move the crossing point up and down, from 20% to 80%, for BER optimization purposes.

The SY88353BL operates from a single +3.3V power supply, over temperatures ranging from -40°C to +85°C. Signals with data rates from 155Mbps up to 3.2Gbps, and as small as10mVPP, can be amplified to drive devices with CML or PECL inputs.

The SY88353L features a Loss-of-Signal (LOS) open-collector TTL output. A programmable Loss-of-Signal level set pin (LOS LVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold sets by LOS LVL and de-asserts low otherwise. The enable bar input (/EN) de-asserts the true output signal without removing the input signal. The LOS output can be fed back to the /EN input to maintain output stability under a loss-of-signal condition. Typically, 3.3dB LOS hysteresis is provided to prevent chattering.