General Description

The SY88403BL is a low-power limiting post amplifier

optimized for copper applications. 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

SY88403BL quantizes these signals and outputs

typically 800 mVPP voltage-limited waveforms.

The SY88403BL operates from a single +3.3V ±10

power supply, over an industrial temperature range of

−40°C to +85°C. With its wide bandwidth and high gain,

signals with data rates up to 4.25 Gbps and as small as

5 mVPP can be amplified to drive devices with CML

inputs or AC-coupled PECL inputs.

The SY88403BL incorporates a loss-of-signal (LOS)

open-collector TTL output with internal 4.75 kΩ pull-up

resistor. A programmable loss-of-signal level set pin

(LOSLVL) sets the sensitivity of the input amplitude

detection.

LOS asserts high if the input amplitude falls below the

threshold set by LOSLVL and de-asserts low

otherwise. LOS can be fed back to the enable bar (/EN)

input to maintain output stability under a loss of signal

condition. /EN de-asserts the true output signal without

removing the input signal. Typically, 3.5 dB LOS

hysteresis is provided to prevent chattering.

Features

• Multi-Rate up to 4.25 Gbps Operation

• 5 mVPP Input Sensitivity

• Low Noise 50Ω CML Data Outputs

- 800 mVPP Output Swing

- 60 ps Edge Rates

- 1psRMS Typ. Random Jitter

- 10psPP Typ. Deterministic Jitter

• Chatter-Free Loss-of-Signal (LOS) Output

- 3.5 dB Electrical Hysteresis

- OC-TTL Output with Internal 4.75 kΩ Pull-Up

Resistor

• Programmable LOS Sensitivity Using Single

External Resistor

• Internal 50Ω Data Input Termination

• TTL /EN Input Allows Feedback from LOS

• Wide Operating Range:

- Single 3.3V ±10 Power Supply

- Industrial Temperature Range: −40°C to

+85°C

• Available in a 16-pin QFN Package

Applications

• 1.062 Gbps, 2.125 Gbps, and 4.25 Gbps Fibre

Channel

• Cable Driver

• Small Form Factor (SFF) and Small Form Factor

Pluggable (SFP) Transceivers

• High-Gain Line Driver and Line Receiver