RGR2622-FP - Agilent / Hewlett-Packard

406

Fiber Optic “Light to Logic”

Receiver with Clock Recovery

Preliminary Technical Data

RGR2622

Features

• Light to Logic 20-Pin DIP

Receiver Offers ECL

Compatibility

• Sensitivity:

–31 dBm

• Phase-Locked Loop (PLL)

Timing Recovery Circuit

• Meets All SONET Jitter

Requirements

(CCITT G.958)

• Single +5 V Supply,

Typically <1.00 W

• SONET/SDH Compliant

Applications

• Telecommunication

Networks

• SONET OC12 and SDH

STM4 Compatible

• Local and Metropolitan Area

Networks

• ATM Single Mode Public

Network

• Military Communications

and Control Systems

• Digital Cable TV Networks

Description

The RGR2622 receiver provides

optical signal conversion and

processing. It converts 1200 nm

to 1600 nm wavelength lightwave

information into an electrical

signal at data rates of 622 Mb/s.

Each receiver contains an InGaAs

PIN photodiode, a high sensitiv-

ity, wide dynamic range transim-

pedance amplifier, capacitively

coupled to a PLL based clock

recovery circuit. The clock and

data outputs are retimed

complementary PECL.

A complementary CMOS

compatible low light alarm is also

provided.

Preliminary Product Disclaimer

This preliminary data sheet is provided to assist you in the evaluation of engineering samples of the product which is under development.

Until Hewlett-Packard releases this product for general sales, HP reserves the right to alter prices, specifications, features, capabilities,

function, manufacturing release dates, and even general availability of the product at any time.

(5/97)

407

Pins 12, 14, ALARM, ALARM:

These pins provide complemen-

tary ALARM and ALARM outputs.

This is the low light alarm.

ALARM goes to a logic low

(CMOS compatible) state when

the optical power drops below

the threshold level (insufficient

optical power).

The optical power must increase

to a higher level than the level

where the alarm went low before

ALARM will return to a logic

high. This difference is the alarm

hysteresis.

Pins 17, 18, 19, 20 NC:

These pins are not connected.

Connection Diagram

Top View

Pin Descriptions

Pins 1, 2, 3, 6, 8, 13, 15, 16,

GND:

These pins should be connected

to the circuit ground.

Pins 4, 5, CLOCK, CLOCK:

These pins provide

complementary PECL CLOCK

and CLOCK outputs.

Pins 7, 9, DATA, DATA:

These pins provide complemen-

tary PECL DATA and DATA

outputs.

The RGR2622 DATA output is

noninverting, an optical pulse

causes the DATA output to go to

the PECL logic high state (+4 V

nominal).

Pin 10, PD Bias:

This pin must be connected to

any voltage from 0 V (GND) to

–5 V. This provides the photo-

diode bias. The current drawn is

directly proportional to the

average received photocurrent.

I = Responsivity x Mean Power.

The Responsivity will be between

0.8 A/W and 1.0 A/W.

Pin 11, +5 V:

This pin should be connected to

+5 V supply. The network shown

below should be placed as close

as possible to pin 11.

GND

CLOCK

GND

DATA

GND

DATA

PD BIAS

GND

ALARM

GND

ALARM

+5 V

FIBER PIGTAIL

1 µH +5 V

100 nF 100 nF10 µF

PIN 11

408

Functional Description

Design

The receiver contains an InGaAsP

photodetector, transimpedance

amplifier and interface amplifier

circuit, including a clock recovery

and data retiming function. It is

designed with a multimode fiber

pigtail to allow maximum

flexibility in connector options.

The interface amplifier is ac

coupled to the preamplifier

circuit.

Terminating the Outputs

The data outputs of the RGR2622

are PECL compatible. Care

should be taken to match termin-

ation impedances to the intercon-

nect to minimize reflection

effects. In order to balance the

drive currents drawn from the

RGR2622 all serial data outputs

(DATA and DATA, CLOCK and

CLOCK) should be terminated

identically, even if only one

output is used.

This will lower the power supply

noise generated by the RGR2622

and improve performance at low

optical input power levels.

Power Supplies

The RGR2622 will operate to

specifications with a single +5 V

power supply (Pin 10 grounded).

The –5 V pin bias is provided to

maintain functional compatibility

with second sources.

Circuit Layout

The RGR2622 uses very high

bandwidth circuitry to achieve its

high level of performance. Care

must be taken to ensure stable

operation. The use of ground

planes and transmission line

interconnects is required. The use

of a standard evaluation board is

highly recommended for those

users who are not familiar with

these techniques.

Signal traces should conform to

ECL design rules to prevent

reflections and ringing from

degrading performance. Useful

guidelines are contained in ECL

manufacturer design manuals.

Manufacturing

The fiber pigtail on the device

requires normal fiber handling

considerations. Care should be

taken to avoid tight bends as well

as excessive tension on the fiber

pigtail.

The allowable temperature range

for the RGR2622 is limited by the

material used in the pigtail.

Exposure to temperatures over

+85°C is not recommended. Low

profile sockets or hand soldering

are recommended for this part.

Figure 1. Block Diagram.

MID

AMP LOW PASS FILTER PLL

CLOCK AND

DATA RECOVERY

(+5 V)

GND (0 V)

ALARM

ALARM DATA

DATA

CLOCK

NEG

(-5 V OR GND)

AMP

+5 V

0 V

409

Performance Specifications

Absolute Maximum Ratings

Absolute maximum limits mean that no catastrophic damage will occur if the product is subjected to these ratings for short periods, provided that

each limiting parameter is in isolation and all other parameters have values within the performance specification. It should not be assumed that

limiting values of more than one parameter can be applied to the product at the same time.

Parameter Symbol Minimum Maximum Units Note

Supply Voltage VCC –0.5 +5.5 V 1

Supply Voltage VNEG –10 +0.5 V 1

Environmental Parameters

Parameter Symbol Minimum Maximum Units Note

Operating Temperature - –40 +85 °C-

Storage Temperature - –40 +85 °C-

Humidity - - 85 %RH -

Electrical Parameters (–40°C to +85°C)

Parameter Symbol Minimum Maximum Units Note

Supply Voltage VCC 4.75 5.25 V -

VCC Supply Current - - 250 mA 4

DATA Output Level (high) - 3.8 4.15 V 2, 3

DATA Output Level (low) - 3.1 3.5 V 2, 3

ALARM Output Level (high) V off 4.5 5.0 V 3

ALARM Output Level (low) V on 0 0.5 V 3

Notes:

1. On an RGR2622 VCC of –0.5 V and VNEG of +0.5 V may not be applied simultaneously.

2. Output terminated to (VCC -2) with 50 Ω load or equivalent.

3. Output voltages are for VCC = 5.0 V.

4. Outputs not loaded.

410

Optical Parameters (–40°C to +85°C)

Parameter Symbol Minimum Typical Maximum Units Note

Wavelength - 1200 - 1600 nm -

Receiver Sensitivity - - –33.5 –31 dBm 1

Maximum Input Power - –4 - - dBm -

Alarm ON - –40 - –30 dBm -

Hysteresis - 1 - 6 dB -

Alarm Response Time - - - 600 µS-

Reliability Target - - - 2000 FIT -

Fiber Parameters

Fiber Pigtail Typical Units

Core Diameter 50 microns

Cladding Diameter 125 microns

Secondary Coating Diameter 900 microns

Jitter Tolerance ITU G.958 Compliant

Jitter Transfer ITU G.958 Compliant

Jitter Generation ITU G.958 Compliant

Note:

1. At a BER of 1 x 10-10, 223-1 PRBS pattern NRZ data at the line rate with 10:1 extinction ratio. EOL.

411

Drawing Dimensions

Handling Precautions

1. The RGR2622 can be damaged

by current surges or

overvoltage. Power supply

transient precautions should

be taken.

2. Normal handling precautions

for electrostatic sensitive

devices should be taken.

Ordering Information

RGR2622 - XX

Connector:

FP = FC/PC Polish

ST* = ST

SC = SC

DN = DN

Allowable part numbers

RGR2622

*ST is a registered trademark of AT&T.

ALL DIMENSIONS IN MILLIMETERS

MIN. NOM.

32.9

–

16.0

–

2.6

–

2.7

–

400

–

2.54

0.46

–

10.16

–

∅G

DIM.

F∅G

B A

MAX.

33.2

17.5

16.3

9.27

2.95

–

3.2

4.64

–

1220

110

20 11