SY88933AL 3.3V, 1.25Gbps PECL High-Sensitivity Limiting Post Amplifier w/TTL Signal Detect General Description Features The SY88933AL high-sensitivity limiting post amplifier Single 3.3V power supply is designed for use in fiber-optic receivers. The device DC-to-1.25Gbps operation connects to typical transimpedance amplifiers (TIAs). Low-noise PECL data outputs The linear signal output from TIAs can contain High gain SD significant amounts of noise and may vary in amplitude over time. The SY88933AL quantizes these signals Chatter-free open-collector TTL signal detect (SD) and outputs PECL level waveforms. output with internal 4.75k pull-up resistor The SY88933AL operates from a single +3.3V power TTL EN input o supply, over temperatures ranging from 40C to Programmable SD level set (SD ) LVL o +85 C. With its wide bandwidth and high gain, signal Available in a tiny 10-pin MSOP package with data rates up to 1.25Gbps and as small as 5mV PP Pin-compatible with SY88933V can be amplified to drive devices with PECL inputs. The SY88933AL generates a high gain signal-detect Applications (SD) open-collector TTL output. The SD function has a high gain input stage for increased sensitivity. A GPON/BPON/EPON/GEPON programmable signal-detect level set pin (SD ) sets LVL Gigabit Ethernet the sensitivity of the input amplitude detection. SD 531Mbps and 1062Mbps Fibre Channel asserts high if the input amplitude rises above the OC-3 and OC-12 SONET/SDH threshold set by SD and de-asserts low otherwise. LVL High-gain line driver and line receiver The enable input (EN) de-asserts the true output signal without removing the input signal. The SD output can Low-gain TIA interface be fed back to the EN input to maintain output stability under a loss-of-signal condition. Typically, 3.4dB SD Markets hysteresis is provided to prevent chattering. FTTX All support documentation can be found on Micrels Optical transceiver web site at: www.micrel.com. Datacom/telecom MLF and MicroLeadFrame are registered trademarks of Amkor Technology. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. SY88933AL Typical Application Circuit 2 M9999-021207-B February 2007 hbwhelp micrel.com or (408) 955-1690