1

SY88803V

Micrel

3.3V/5V 155Mbps PECL LOW POWER

LIMITING POST AMPLIFIER W/TTL LOS

SY88803V

Rev.: A

Amendment: /0

Issue Date:

March 2003

TYPICAL APPLICATIONS CIRCUIT

APPLICATIONS

s 155Mbps SONET/SDH

s Small form factor transceivers

s High-gain line driver and line receiver

s Single 3.3V or 5V power supply

s Up to 155Mbps operation

s Low noise PECL data outputs

s Chatter-free TTL Loss-of-Signal (LOS) output

s TTL /EN input

s Programmable LOS level set (LOS

s Available in a tiny 10-pin MSOP (3mm) package

FEATURES

DESCRIPTION

The SY88803V low power 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 SY88803V

quantizes these signals and outputs PECL level waveforms.

The SY88803V operates from a single +3.3V or +5V

power supply, over temperatures ranging from –40

°C to

+85

°C. With its wide bandwidth and high gain, signals with

data rates up to 155Mbps and as small as 5mVp-p can be

amplified to drive devices with PECL inputs.

The SY88803V generates a TTL LOS output. A

programmable loss-of-signal level set pin (LOS

sensitivity of the input amplitude detection. LOS asserts

high if the input amplitude falls below the threshold set by

LOS

true output signal without removing the input signal. Typically

4.6dB loss-of-signal hysteresis is provided to prevent

chattering.

/EN

GND

GND

To

CDR

SY88803V

3k

Ω

From

Transimpedance

Amp.

0.1

µF

0.1

µF

0.1

µF

0.1

µF

LOS

50

Ω

2k

Ω

50

Ω

100

Ω