SY88933AL

3.3V, 1.25Gbps PECL High-Sensitivity

Limiting Post Amplifier w/TTL Signal Detect

MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

May 2005

M9999-051205

General Description

The SY88933AL high-sensitivity limiting post amplifier

is designed for use in fiber-optic receivers. 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 SY88933AL quantizes these signals

and outputs PECL level waveforms.

The SY88933AL operates from a single +3.3V power

supply, over temperatures ranging from –40

+85

can be amplified to drive devices with PECL inputs.

The SY88933AL generates a high gain signal-detect

(SD) open-collector TTL output. The SD function has a

high gain input stage for increased sensitivity. A

the sensitivity of the input amplitude detection. SD

asserts high if the input amplitude rises above the

The enable input (EN) de-asserts the true output signal

without removing the input signal. The SD output can

be fed back to the EN input to maintain output stability

under a loss-of-signal condition. Typically, 3.4dB SD

hysteresis is provided to prevent chattering.

All support documentation can be found on Micrel’s

Features

• Single 3.3V power supply

• DC-to-1.25Gbps operation

• Low-noise PECL data outputs

• High gain SD

• Chatter-free open-collector TTL signal detect (SD)

output with internal 4.75k

Ω pull-up resistor

• TTL EN input

• Available in a tiny 10-pin MSOP package

• Pin-compatible with SY88933V

Applications

• GPON/BPON/EPON/GEPON

• Gigabit Ethernet

• 531Mbps and 1062Mbps Fibre Channel

• OC-3 and OC-12 SONET/SDH

• High-gain line driver and line receiver

• Low-gain TIA interface

Markets

• FTTX

• Optical transceiver

• Datacom/telecom