The SY88432L is a low power transceiver device that integrates a 4.25Gbps FP/DFB laser diode driver with a wide-sensitivity limiting post amplifier. This low power device is designed for use in fiber-optic optical modules for multi-rate applications up to 4.25Gbps. The SY88432L transmitter section can output up to 60mA of modulation current with fast rise and fall times and is designed to be AC-coupled to the laser. The transmitter output stage incorporates a transmit disable feature and integrated 50Ω input impedance referenced to VCC. The receiver section’s limiting post amplifier connects to a typical trans-impedance amplifier (TIA) to amplify the incoming weak signal from the ROSA and outputs normalized received data in CML format at the output. The receiver offers a wide LOS (loss of signal) range and is able to detect input signals of as low as 5mVpp and as high as 80mVpp. A programmable loss-of-signal level set pin (LOSLVL) sets the sensitivity of the input amplitude detection. The LOS or SD (signal-detect) is user selectable and the LOS/SD signal can be fed back to the JAM input to implement the SQUELCH function that maintains output stability under a loss-of-signal condition. The receiver input should be AC-coupled. The SY88432L interfaces with Micrel’s highly advanced optical module controller MIC3003 as an easy-to-use chipset solution for CSFP/SFP/CSFF/SFF optical module applications. The MIC3003 allows for both modulation and bias current control, with automatic power control (APC) and temperature compensation. The SY88432L operates on a single 3.3V power supply and is available in a 24 lead, 4mm x 4mm QFN package.

Additional Features

• Multi-rate operation up to 4.25Gbps
• Single, wide range power supply: 3.3V ±10%
• Industrial temp range: -40°C to +85°C
• MIC3003 compatible
• Transmitter – FP/DFP Laser Diode Driver
• Modulation current up to 60mA
• AC coupled laser diode modulation
• Voltage controlled modulation current
• Rise/Fall times 65ps (typical)
• TX Disable with internal 75kΩ pull down resistor
• Integrated 50&Omega input impedance to V CC
• Receiver – Limiting Post Amplifier
• Wide differential input range (5mVpp – 1800mVpp)
• Wide LOS range (8mVpp – 80mVpp) with 3.5dB typical electrical hysteresis
• Programmable LOS level (LOSLVL) sensitivity
• Selectable LOS or SD output
• TTL compatible JAM input with internal pull up
• Low-noise CML data outputs with integrated 50Ω termination impedance
• Rise/Fall times 60ps (typical)
• Low-noise CML data inputs with integrated 50Ω termination impedance to internal reference V REF