SY88903AL Datasheet, PDF (1/9 Pages) Micrel Semiconductor – 3.3V, Burst Mode 1.25Gbps PECL High-Sensitivity Limiting Post Amplifier with TTL Loss-of-Signal

SY88903AL
3.3V, Burst Mode 1.25Gbps PECL High-
Sensitivity Limiting Post Amplifier with TTL
Loss-of-Signal
General Description
The SY88903AL, burst mode, high-sensitivity limiting
post amplifier is designed for use in fiber-optic receivers,
specially optimized for passive optical networks (PONs).
The device connects to typical transimpedance
amplifiers (TIAs). The linear signal output from TIAs can
contain significant amounts of noise and may vary in
amplitude over time. The SY88903AL quantizes these
signals and outputs PECL level waveforms.
The SY88903AL operates from a single +3.3V power
supply, over temperatures ranging from –40^oC to +85^oC.
Signals with data rates from 622Mbps up to 1.25Gbps,
and as small as 5mV_pp, can be amplified to drive
devices with PECL inputs.
The SY88903AL generates a Loss-of-Signal (LOS)
open-collector TTL output. 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, 3.4dB LOS hysteresis is provided to
prevent chattering.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
Features
• Single 3.3V power supply
• Fast LOS release/assert (<500ns) time for PON
applications
• 622Mbps to 1.25Gbps operation
• Low-noise PECL data outputs
• High gain LOS
• Chatter-free Open-Collector TTL signal detect (LOS)
output with internal 4.75kΩ pull-up resistor
• TTL /EN input
• Programmable LOS level set (LOS_LVL)
• Available in a tiny 10-pin MSOP package
Applications
• GPON/GEPON/EPON
• Gigabit Ethernet, 1062Mbps Fibre Channel
• OC-12/24 SONET/SDH
• Low-gain TIA interface
• High-gain line driver and line receiver
Markets
• FTTH/FTTP
• Datacom/telecom
• Optical transceiver
February 2007
1
M9999-021707-D
[e-mail] or [phone]