The SY88303BL low-power limiting post amplifiers are designed for use in fiber-optic receivers. These devices connect to typical transimpedance amplifiers (TIAs) . Th e linear signal output from TIAs can contain significant amounts of noise and may vary in amplitude over time. The SY88303BL quantizes these signals and output CML-level waveforms. The SY88303BL operates from a single +3.3V power supply, over temperatures ranging from -40°C to +85°C. With their wide bandwidth and high gain, signals with data rates up to 3.2Gbps, and as small as 10mVPP , can be amplified to drive devices with CML/PECL inputs. The device generates a loss-of-signal (LOS) open-collector TTL output. The LOS function is optimized to detect a wide input range, as shown in the typical operating characteristic curve on Page 6. 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, 3.5dB LOS hysteresis is provided to prevent chattering.