SY88349NDL

2.5Gbps Burst-Mode Limiting Amplifier

with Ultra-Fast Signal Assert Timing

January 2012

2

M9999-010212-C

General Description

The SY88349NDL is a high-sensitivity, burst-mode

capable limiting post amplifier designed for optical line

terminal (OLT) receiver applications. The SY88349NDL

satisfies the strict timing restrictions of the GPON

standards by providing ultra-fast loss-of-signal (LOS) or

Signal-Detect (SD) output. Auto reset and manual reset

options are provided to control LOS/SD output timing. For

increased flexibility, this device also includes an option to

select between LOS or SD output. The device can be

connected

to

burst-mode

capable

transimpedance

amplifiers (TIAs) using AC or DC coupling.

The SY88349NDL generates a high-gain LOS or SD

LVTTL output. A programmable LOS/SD level set pin

detection. When LOS/SD SEL pin is left open or tied to

the input amplitude rises above the threshold sets by

SEL pin is set low or tied to GND, JAM is active low, LOS

is selected and asserts low if the input amplitude rises

high otherwise. The LOS/SD output can be fed back to the

JAM input to maintain output stability under an invalid

signal conditions. Typically, 4dB

 5dB SD hysteresis is

provided to prevent chattering.

The SY88349NDL also features a selectable proprietary

noise discriminator that aids by filtering out input signals

that do not qualify as a 2.5Gbps GPON preamble signal in

the initial startup phase. This feature minimizes false SD

asserts that can be triggered by random noise.

The SY88349NDL operates from a single +3.3V power

supply, over temperatures ranging from –40

C to +85C.

With its wide bandwidth and high gain, signals up to

2.5Gbps and as small as 5mVpp can be amplified to drive

devices with CML inputs.

Data sheets and support documentation can be found on

Features

 <5ns SD assert (LOS deassert) time

 Proprietary noise discriminator feature

 Option to AUTO RESET or manual RESET LOS/SD

output

 Selectable LOS/SD option

 Up to 2.5Gbps operation

 Low-noise CML data outputs

 5mVpp input sensitivity

 High-sensitivity LOS/SD detect

 LVTTL LOS/SD output with an external pull-up resistor

 Squelching function to disable output

 Single 3.3V power supply

 Available in a 16-pin (3mm  3mm) QFN package

Applications

 XGPON.1/GEPON/GPON

 Gigabit Ethernet

 Fibre Channel

 OC-3/12/24/48 SONET/SDH

 High-gain line driver and line receiver

 Low-gain TIA interface

Markets

 FTTH

 Datacom/Telecom

 Optical transceiver