The SY88343BL low-power limiting post amplifier is designed for use in fiber-optic receivers. The device connects to typical transimpedance amplifiers (TIAs) that are AC-coupled. Th e linear signal output from TIAs can contain significant amounts of noise and may vary in amplitude over time. The SY88343BL quantizes these signals and outputs CML-level waveforms.

The SY88343BL operates from a single +3.3V power supply, over temperatures ranging from -40°C to +85°C. With its wide bandwidth and high gain, signals with data rates up to 3.2Gbps and as small as 5mVPP can be amplified to drive devices with CML inputs or AC-coupled CML/PECL inputs.

The SY88343BL generates a high-gain loss-of-signal (LOS) open-collector TTL output. The LOS function has a high gain input stage for increased sensitivity. 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 set 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, 3.5dB LOS hysteresis is provided to prevent chattering.