SY88147DL Datasheet, PDF (1/10 Pages) Micrel Semiconductor – 3.3V, 1.25Gbps PECL Limiting Post Amplifier w/High Gain TTL Loss-of-Signal

SY88147DL
3.3V, 1.25Gbps PECL Limiting Post
Amplifier w/High Gain TTL Loss-of-Signal
General Description
The SY88147DL is a high-sensitivity limiting post
amplifier designed for use in fiber-optic receivers. These
devices connect 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 SY88147DL quantizes these signals and
outputs PECL level waveforms.
The SY88147DL operates from a single +3.3V power
supply, over temperatures ranging from –40^oC to +85^oC.
With its wide bandwidth and high gain, signals with data
rates up to 1.25Gbps, and as small as 5mV_PP, can be
amplified to drive devices with PECL inputs.
The SY88147DL generates a high-gain loss-of-signal
(LOS) open-collector TTL output. The LOS function has
a high gain input stage for increased sensitivity. 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
3.5dB 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
• DC to 1.25Gbps operation
• Low-noise PECL data outputs
• High-gain LOS
• Chatter-free Open-Collector TTL Loss of Signal
(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
Applications
• APON/BPON/EPON/GEPON/GPON
• Gigabit Ethernet
• 531Mbps and 1062Mbps Fibre Channel
• OC-3 and OC-12/24 SONET/SDH
• High-gain line driver and line receiver
• Low-gain TIA interface
Markets
• FTTH
• Datacom/Telecom
• Optical transceiver
February 2007
1
M9999-021207-B
[e-mail] or [phone]