MICROCHIP SY88903VKG-TR

The SY88903V limiting post amplifier with its high gain and wide bandwidth is ideal for use as a post amplifier in fiber optic receivers with data rates up to 1.25Gbps. Signals as small as 5mV_pp can be amplified to drive devices with PECL inputs. The SY88903V generates a chatter-free, Loss-of-Signal (LOS), open-collector TTL output. The SY88903V is an integrated limiting amplifier intended for high-frequency fiber optic applications. The circuit connects to typical transimpedance amplifiers found within a fiber optics link. The linear signal output from a transimpedance amplifier can contain significant amounts of noise, and may vary in amplitude over time. The SY88903V limiting amplifier quantizes the signal and outputs a voltage-limited waveform. The /EN pin allows the user to disable the output signal without removing the input signal. The SY88903V incorporates a programmable level detect function to identify when the input signal has been lost. This information can be fed back to the /EN input of the device to maintain stability under loss of signal condition. The sensitivity of the level detection can be adjusted using LOS_LVL. The LOS_LVL voltage can be set by connecting a resistor divider between V_CC and V_REF. “Typical Characteristics” show the relationship between input level sensitivity and the voltage set on LOS_LVL. The LOS output is a TTL open-collector output that requires a pull-up resistor for proper operation.

• 3.3V and 5V power supply option
• Up to 1.25Gbps operation
• Low noise
• Chatter-free LOS generation
• Open collector TTL LOS output
• TTL /EN Input
• Differential PECL inputs for data
• Single power supply
• Designed for use with laser diode driver and controller
• Available in a tiny 10-pin (3mm×3mm) MSOP

• 1.25Gbps Gigabit Ethernet
• 531Mbps and 1062Mbps Fibre Channel
• 622Mbps SONET
• Gigabit Interface Converter