Agilent Technologies N4970A User manual

Agilent N4970A
PRBS Generator 10 Gb/s
User Guide

Notices
© Agilent Technologies, Inc. 2012
No part of this manual may be reproduced in any
form or by any means (including electronic
storage and retrieval or translation into a foreign
language) without prior agreement and written
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governed by United States and international
copyright laws.
Manual Part Number
N4970-91021
Edition
Second edition, May 2013
Agilent Technologies, Deutschland GmbH
Herrenberger Str. 130
71034 Böblingen, Germany
For Assistance and Support
http://www.agilent.com/find/assist
Limitation of Warranty
The foregoing warranty shall not apply to defects
resulting from improper or inadequate
maintenance by Buyer, Buyer-supplied software or
interfacing, unauthorized modification or misuse,
operation outside of the environmental
specifications for the product, or improper site
preparation or maintenance. No other warranty is
expressed or implied. Agilent Technologies
specifically disclaims the implied warranties of
Merchantability and Fitness for a Particular
Purpose.
Warranty
The material contained in this document is
provided “as is,” and is subject to being
changed, without notice, in future editions.
Further, to the maximum extent permitted by
applicable law, Agilent disclaims all warranties,
either express or implied, with regard to this
manual and any information contained herein,
including but not limited to the implied
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errors or for incidental or consequential
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the user have a separate written agreement with
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Software is delivered and licensed as
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“commercial item” as defined in FAR 2.101(a) or
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users will receive no greater than Limited Rights
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applicable in any technical data.
Safety Notices
A CAUTION notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in damage to the product
or loss of important data. Do not
proceed beyond a CAUTION notice until
the indicated conditions are fully
understood and met.
A WARNING notice denotes a hazard.
It calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in personal injury or
death. Do not proceed beyond a
WARNING notice until the indicated
conditions are fully understood and
met.
A NOTE provides important or special
information.
CAUTION
WARNING
NOTE

Safety Summary
General Safety Precautions
The following general safety precautions
must be observed during all phases of
operation of this instrument. Failure to
comply with these precautions or with
specific warnings elsewhere in this manual
violates safety standards of design,
manufacture, and intended use of the
instrument.
Agilent Technologies Inc. assumes no
liability for the customer's failure to comply
with these requirements.
Before operation, review the instrument and
manual for safety markings and instructions.
You must follow these to ensure safe
operation and to maintain the instrument in
safe condition.
Initial Inspection
Inspect the shipping container for damage. If
there is damage to the container or
cushioning, keep them until you have
checked the contents of the shipment for
completeness and verified the instrument
both mechanically and electrically. The
Performance Tests give procedures for
checking the operation of the instrument. If
the contents are incomplete, mechanical
damage or defect is apparent, or if an
instrument does not pass the operator’s
checks, notify the nearest Agilent
Technologies Sales/Service Office.
WARNING To avoid hazardous electrical
shock, do not perform electrical tests when
there are signs of shipping damage to any
portion of the outer enclosure (covers,
panels, etc.).
General
This product is a Safety Class 1 product
(provided with a protective earthing ground
incorporated in the power cord). The mains
plug shall only be inserted in a socket outlet
provided with a protective earth contact.
Any interruption of the protective conductor,
inside or outside of the instrument, will
make the instrument dangerous. Intentional
interruption is prohibited.
Environment Conditions
This instrument is intended for indoor use in
an installation category II, pollution degree 2
environment per IEC 61010 Second Edition
and 664 respectively. It is designed to
operate within a temperature range of 10 to
40 °C at a maximum relative humidity of 80%
for temperatures up to 31 °C, decreasing
linearly to 50% relative humidity at 40 °C at
an altitude of 2000 meters.
This module can be stored or shipped at
temperatures between -40°C and +70°C.
Protect the module from temperature
extremes that may cause condensation
within it.
Before Applying Power
Verify that all safety precautions are taken.
The power cable inlet of the instrument
serves as a device to disconnect from the
mains in case of hazard. The instrument
must be positioned so that the operator can
easily access the power cable inlet. When
the instrument is rack mounted the rack
must be provided with an easily accessible
mains switch.
Ground the Instrument
Install the instrument so that the ON / OFF
switch is readily identifiable and is easily
reached by the operator. The ON / OFF
switch is the instrument disconnecting
device. It disconnects the mains circuits
from the mains supply before other parts of
the instrument. Or the detachable power
cord can be removed from the electrical
supply. Alternately, an externally installed
switch or circuit breaker which is readily
identifiable and is easily reached by the
operator may be used as a disconnecting
device.
Do Not Operate in an Explosive
Atmosphere
Do not operate the instrument in the
presence of flammable gases or fumes.
Do Not Remove the Instrument
Cover
Operating personnel must not remove
instrument covers. Component replacement
and internal adjustments must be made only
by qualified personnel.
Instruments that appear damaged or
defective should be made inoperative and
secured against unintended operation until
they can be repaired by qualified service
personnel.

Symbols on Instruments
Indicates warning or caution. If you see this
symbol on a product, you must refer to the
manuals for specific Warning or Caution
information to avoid personal injury or damage to
the product.
C-Tick Conformity Mark of the Australian ACA for
EMC compliance.
Indicates that protective earthing ground is
incorporated in the power cord.
This mark indicates compliance with the Canadian
EMC regulations.
ISM 1-A
This text denotes the instrument is an Industrial
Scientific and Medical Group 1 Class A product.
CE Marking to state compliance within the
European Community: This product is in
conformity with the relevant European Directives:
EMC Directive 2004/108/EC and Low Voltage
Directive 2006/95/EC.
This symbol indicates that internal circuits can be
damaged by electrostatic discharge (ESD),
therefore, avoid applying static discharges to the
panel input connectors.
China RoHS regulations include requirements
related to packaging, and require compliance to
China standard GB18455-2001. This symbol
indicates compliance with the China RoHS
regulations for paper/fiberboard packaging.
Indicates the time period during which no
hazardous or toxic substance elements are
expected to leak or deteriorate during normal use.
Forty years is the expected useful life of the
product.
The Korean Certification (KC) mark is required for
products that are subject to legally compulsory
certification.
The KC mark includes the marking’s identifier
code that has up to 26 digits and follows this
format: KCC-VWX-YYY-ZZZZZZZZZZZZZ.
This symbol indicates that the instrument requires
alternating current (AC) input.
This symbol indicates that the power line switch
is in the ON position.
O
This symbol indicates that the power line switch
is in the OFF position.

Environmental Information
This product complies with the WEEE Directive
(2002/96/EC) marketing requirements. The affixed
label indicates that you must not discard this
electrical/electronic product in domestic
household waste.
Product category: With reference to the equipment
types in the WEEE Directive Annexure I, this
product is classed as a “Monitoring and Control
instrumentation” product.
Do not dispose in domestic household waste.
To return unwanted products, contact your local
Agilent office, or see
www.agilent.com/environment/product/ for more
information.

Contents
PRBS Generator 10 Gb/s User Guide 7
Contents
1Getting Started ......................................................................................................... 9
1.1 Unpacking and Installation ............................................................................ 9
1.2 Important Notes............................................................................................. 10
1.3 Performance Recommendations................................................................. 10
2N4970A Operation Overview................................................................................. 11
2.1 Features........................................................................................................... 11
2.2 N4970A System Overview............................................................................ 12
2.3 Options............................................................................................................ 13
2.4 Front Panel Quick Reference....................................................................... 14
2.5 Rear Panel Quick Reference........................................................................ 15
2.6 Safety and Regulatory................................................................................... 18
2.6.1 Declaration of Conformity............................................................. 18
3Performance Specifications.................................................................................. 19
3.1 General............................................................................................................ 19
3.2 N4970A PRBS Generator Specifications................................................... 20
4Operation ................................................................................................................. 21
4.1 General Information ...................................................................................... 21
4.1.1 Performance Recommendations.................................................. 22
4.1.2 Connector Care............................................................................... 22
4.2 Configuring Patterns or Mark Density ....................................................... 23
4.3 Resetting the N4970A................................................................................... 24
4.4 Input and Output Connectors...................................................................... 24
4.5 System Verification ....................................................................................... 25
4.6 Simple Functional Example of N4970A use.............................................. 28
5Returning the N4970A to Agilent Technologies................................................ 29

Getting Started
8 PRBS Generator 10 Gb/s User Guide

Getting Started
PRBS Generator 10 Gb/s User Guide 9
1Getting Started
1.1 Unpacking and Installation
The N4970A PRBS generator 10 Gb/s is shipped with all the accessories
required for the self-test mode and verification.
The shipment includes:
•N4970A PRBS generator 10 Gb/s
•AC power converter module
•AC power cord
•CD containing the N4970A user guide and N4970A data sheet
If this product is not used as specified, the protection provided by the
equipment could be impaired. This product must be used in a normal
condition (in which all means for protection are intact) only.
Before switching on this instrument, make sure the supply voltage is in the
specified range.
This instrument has auto ranging line voltage input. Be sure the supply
voltage is within the specified range.
To prevent damage to the instrument, make all RF connections between the
N4970A and the DUT or test equipment BEFORE applying AC power to the
N4970A. Also, remove AC power from the N4970A instrument before
disconnecting any RF connections.

Getting Started
10 PRBS Generator 10 Gb/s User Guide
In an ESD-safe environment, carefully remove the N4970A from the packaging.
Install on a flat surface with unobstructed air flow to the back panel.
Make all
RF connections between the N4970A and the DUT or test equipment BEFORE
applying AC power by plugging the converter module into the N4970A. Also
,
remove AC power from the N4970A instrument before disconnecting any RF
connections.
Plug the AC power cord into the power converter module and a
wall socket, then plug the converter module into the N4970A.
1.2 Important Notes
•
Use ESD protection at all times when using the system.
•Review min/max specifications before applying input signals.
•Use only SMA-connectors on the RF ports.
•Use dust jackets on unused back panel connectors.
•Situate the instrument away from heat sources.
1.3 Performance Recommendations
1.
When using differential-mode connections, ensure the cables are
phase balanced.
2. Differential connectors may be used single-ended if second end
terminated in 50 Ω.
3. Use high quality cables and connector savers (or adaptors).
4. Keep cable lengths short and minimize number of cable bends.
5. Use a 7 to 10 in-lbs torque wrench when attaching connectors.

N4970A Operation Overview
PRBS Generator 10 Gb/s User Guide 11
2N4970A Operation Overview
The N4970A is a Pseudo Random Bit Stream (PRBS) generator with an
internal clock that can be factory set from a selection of frequencies around
10 GHz, and can also be user-
configured to use a 0.05 to 12.5 GHz clock signal
from an external source.
The N4970A features low jitter, fast rise and fall times, and a clean eye
pattern. The source provides five selectable pattern lengths and three
selectable mark densities. The N4970A comes in an easy to use compact
(3.5 x 3.5 x 1.0 inch) package.
The PRBS generator provides the "clean eye" needed to evaluate the
performance of optical system components or complete systems, e.g.
SONET/SDH, 10 Gb/s ethernet, XAUI, etc.
2.1 Features
•
Single-frequency clock source
•Wide operating range, up to 12.5 Gb/s (external clock)
•RMS jitter ~ 1.0 ps
•Fast rise/fall times
•Small size: 3.5" x 3.5" x 1"
•Multiple output patterns: 27-1, 210-1, 215-1, 223-1, 231-1
•Multiple mark ratios: 1/2, 1/4, 1/8
•Differential outputs

N4970A Operation Overview
12 PRBS Generator 10 Gb/s User Guide
2.2 N4970A System Overview
The N4970A provides a Pseudo Random Bit Stream (PRBS) referenced to
either the factory-set internal clock frequency or an external clock (0.05 GHz
to 12.5 GHz). The N4970A generates a bit stream equal to the clock
frequency, eg: 9.95328 GHz = 9.95328 Gb/s (SONET 10G).
The PRBS pattern length and mark density features can be selected by the
user. The pattern length and mark density settings are indicated on the front
panel of the N4970A.
When the N4970A is used in conjunction with a digital communications
analyzer, accurate high resolution measurements of electrical and optical
components or systems can be performed.
For R&D applications the N4970A source provides the engineer with a fast
rise/fall time, low jitter data stream which is useful in the development of
datacom/telecom products. Accurate repeatable eye pattern measurements
provide a valuable development tool for evaluating and comparing the
performance of design, or components.
The small size of the N4970A (3.5 x 3.5 x 1.0 inch) allows close placement to
DUT eliminating losses and distortion from long cables. The N4970A factory-
set internal clock can be used to eliminate the need for additional test
equipment clock signal generator or oscilloscope trigger divider.
In the manufacturing environment, the N4970A source provides a cost
effective solution for evaluating and tuning communication systems such as
SONET/SDH, 10 Gb/s Ethernet, fiber channel, XAUI, etc.

N4970A Operation Overview
PRBS Generator 10 Gb/s User Guide 13
Figure 1. 10 Gb/s eye output
2.3 Options
The N4970A is available with the following build options:
•Standard: 10 Gb/s data rate operation 300 mV p-p output
•N4970A-010: extended amplitude range 750 mV p-p output
•N4970A-301: internal clock frequency at 10.66423 GHz
•N4970A-302: internal clock frequency at 10.51875 GHz
•N4970A-303: internal clock frequency at 11.09573 GHz
•N4970A-304: internal clock frequency at 9.95328 GHz
•N4970A-305: internal clock frequency at 10.709225 GHz
•N4970A-306: internal clock frequency at 10.3125 GHz

N4970A Operation Overview
14 PRBS Generator 10 Gb/s User Guide
2.4 Front Panel Quick Reference
Figure 2. N4970A front panel
RESET:
A momentary reset switch provides a means to restart the bit stream from an
all zero condition.
Output: The PRBS signal is available as a differential signal on the SMA female
output terminals. Terminate unused outputs.
Impedance: 50 Ω
Max DC: ± 5 V
Nominal DC: 0 V
AC Level: > 300 mV p-p typical, single-ended
> 750 mV p-p typical, single-ended (Option 010)
ESD sensitive; terminate if unused. DC Blocked.

N4970A Operation Overview
PRBS Generator 10 Gb/s User Guide 15
LED indicators:
Eight LED annunciators are provided on the front panel. The first five indicate
the selected pattern length. The next three indicate
the selected mark density
as illustrated below.
Figure 3. N4970A front panel
2.5 Rear Panel Quick Reference
Figure 4. N4970A rear panel
Power: Negative 5 Vdc @ 1 A (center pin negative) is supplied, by the power supply
module, to this terminal to power the PRBS source. Use only the AC/DC
adapter provided with the N4970A.

N4970A Operation Overview
16 PRBS Generator 10 Gb/s User Guide
Rear connector: Eight sets of pins are provided to select the pattern length and mark density.
A separate pair of pins is provided to allow remote reset. Two jumpers are
used to select the desi
red pattern length and mark density. Install the jumpers
in the desired positions for stand-alone operation. Refer to Figure 5. A cable
can be connected to the pins for remote operation.
CKO output: A female SMA connector is pro
vided for the internal clock output. The clock is
factory-set and cannot be adjusted.
Impedance: 50 Ω
Max DC: ± 5 V
Nominal DC: 0 V
AC output: 600 mV nominal
ESD sensitive; terminate if unused. DC Blocked.
Clk input: A female SMA connector is provided for the PRBS clock input, which
establishes the timing of the PRBS. A rigid coax loop is supplied to connect
the CKO output to the CKI input; supply an external clock signal to the CKI
input after removing the coax loop.
Impedance: 50 Ω
Max DC: ± 5 V
Nominal DC: 0 V
AC input: 2 V p-p (+10 dBm) typical < 1 GHz
890 mV p-p (+3 dBm) typical ≥1 GHz
ESD sensitive; terminate if unused. DC Blocked.

N4970A Operation Overview
PRBS Generator 10 Gb/s User Guide 17
CKO/16 output: A female SMA connector provides a divided-by-16 clock output (CKO/16 =
CKI div 16) for triggering.
Impedance: 50 Ω
Max DC: ± 5 V
Nominal DC: 0 V
AC output: 600 mV p-p nominal
DC Blocked.
Figure 5. N4970A rear panel

N4970A Operation Overview
18 PRBS Generator 10 Gb/s User Guide
2.6 Safety and Regulatory
This product has been designed and tested in accordance with accepted
industry standards, and has been supplied in a safe condition. The
documentation contains information and warnings that must be followed by
the user to ensure saf
e operation and to maintain the product in a safe
condition.
Do not remove instrument covers. There are no user serviceable parts
within. Operation of the instrument in a manner not specified by Agilent
Technologies may result in personal injury or loss of life.
To prevent electrical shock, disconnect instrument from mains before
cleaning. Use a dry cloth or one slightly dampened with water to clean the
external case parts. Do not attempt to clean internally.
For continued protection against fire hazard, replace fuses, and or circuit
breakers only with same type and ratings. The use of other fuses, circuit
breakers or materials is prohibited
The Mains wiring and connectors shall be compatible with the connector
used in the premise electrical system. Failure, to ensure adequate earth
grounding by not using the correct components may cause product damage,
and serious injury.
2.6.1 Declaration of Conformity
A EU declaration of conformity is available at
http://regulations.corporate.agilent.com/doc/search.htm

Performance Specifications
PRBS Generator 10 Gb/s User Guide 19
3Performance Specifications
Specifications describe the instrument’s warranted performance. Non-
warranted values are stated as typical. All specifications are valid in a range
from 10 °C to 40 °C ambient temperature after a 30 minute warm-up phase.
3.1 General
Table 1. General and mechanical parameters of N4970A
Operating Temperature +10 to +40 °C
Storage Temperature –40 to +70°C
Power Requirements 42 W External AC Adaptor (included)
•100 to 240 VAC, 50 to 60 Hz
Physical Dimensions (W x H x D) 3.5 x 1.0 x 3.5 inches
Weight 0.22 kg (0.5 lbs)
EMC Complies with European EMC Directive 2004/108/EC
•IEC/EN 61326-1
•CISPR Pub 11 Group 1, class A
•AS/NZS CISPR 11
•ICES/NMB-001
This ISM device complies with Canadian ICES-001.
Cet appareil ISM est conforme a la norme NMB-001 du
Canada.

Performance Specifications
20 PRBS Generator 10 Gb/s User Guide
3.2 N4970A PRBS Generator Specifications
Table 2. N4970A PRBS generator specification table
Parameter Specification
Data rate 0.5 to 12.5 Gb/s1
External clock input rate 0.5 to 12.5 GHz
External clock input power required +10 dBm (2 V p-p) typical < 1.0 GHz
+3 dBm (890 mV p-p) typical ≥ 1.0 GHz
Internal clock rate Single frequency internal oscillator, specify when ordering
Default 10.0 GHz
Option 301 – 10.66423 GHz
Option 302 – 10.51875 GHz
Option 303 – 11.09573 GHz
Option 304 – 9.95328 GHz
Option 305 – 10.709225 GHz
Option 306 – 10.3125 GHz
Internal clock output power 600 mV p-p nominal
Divided clock output Clock rate/16
Divided clock output power 600 mV p-p nominal
PRBS patterns 2n– 1, n=7, 10, 15, 23, 31
Mark space density 1/2, 1/4, 1/8
Data output amplitude (single-ended)2> 300 mV p-p typical
> 750 mV p-p typical (Option 010)
Data output jitter 1.0 ps rms typical2
Data output rise/fall time (20% to 80%) < 25 ps typical
Data output external interface Differential. AC coupled, 50 Ω nominal, female SMA
1With an external clock
2At the internal clock rate