SHF Communication Technologies AG
Wilhelm-von-Siemens-Str. 23 D • 12277 Berlin • Germany
Phone ++49 30 / 772 05 10 • Fax ++49 30 / 753 10 78
E-Mail: sales@shf.de • Web: http://www.shf.de

Datasheet
SHF 11121A40 – 43 Gbps Clock Recovery
Module with Optical Front End

Description
The SHF 11121A Clock Recovery is designed to extract and synchronize the clock from an optical
data stream. It is a clock recovery unit including an optical receiver. The module operates at bit
rates from 39.8 to 43.1 Gbps.
By using a tap coupler, the optical input signal appears at the optical output with only minimum
attenuation.
The extracted optical signal is converted by a receiver to an electrical signal which is processed by
the clock recovery circuit.
The clock recovery circuit contains two separate VCOs which allow operation in two bands. The
lower band spans the range between 39.8 and 41.6 Gbps and the higher band spans the range
between 41.6 and 43.1 Gbps.
Due to the circuit concept a reference frequency of bit rate divided by either 64, 32 or 16 must be
applied to the unit. For better convenience reference oscillators for three standard bit rates (39.813Gbps, 42.656 Gbps and 43.018 Gbps) are included.
The SHF 11121A can be operated locally by the front panel or remote via Ethernet-connection froma PC running the SHF BERT-Control Center. Its programming features allow automatedmeasurements using test programs like Agilent VEE or National Instruments LabView.
The module is a compact solution which offers superb performance while including easy to usefeatures.

FeaturesOptical Receiver•

Optical through port with minimal attenuation•High optical sensitivity•ASK NRZ, RZ and CS-RZ capable

Clock Recovery•

Operating bit rate range from 39.8 to 43.1 Gbps (this includes OC-768 with and without FEC)

•Clock output frequency at half and quarter of the nominal input data bit rate•

Local or remote operation via Ethernet-connection to a PC (SHF BERT Control Center)

Options•Option C40: Full clock output

Applications•

R&D for optical communication systems at bit rates from 40 to 43 Gbps•

Characterization of high speed optical components•

Bit error rate testing•

Optical component and fiber loop testing•

Optical transmitter testing

SHF 11121A – V001 – 25/Oct/2007

SHF reserves the right to change specifications and design without notice

Page 2/8

Block Diagram
OpticalInput(full Bitrate)

Clock Recovery
Module(Bitrate /2)

ClockOutput(Bitrate /4)

PD
OpticalOutputRef.
Input

622.08MHz

Controller

666.51MHz
672.16MHz

Power
SupplyLCDisplay

Keyboard

Ethernet

Precautions with optical connectors
The fiber optic connectors must be kept clean in order to ensure best performance of theSHF 11121A.
Contaminated or damaged fiber ends result in performance degradation. Cover connectors withdust caps when they are not in use.
The following cleaning procedure is recommended for the connector interface of the SHF 11121A
and the external connectors attached to these ports.
•

Before cleaning, the external connectors should be detached from the SHF 11121A.

•To clean the fiber-end face, use a new natural cotton swab that is moistened with isopropylalcohol.

•

We recommend that no other solvents are used to clean the optical surfaces.

•

Move the swab back and forth across the fiber end face several times applying a gentle
pressure.

•Afterwards dry the fiber end face with a clean dry cotton swab or lens paper.

•Do not press the swab or lens paper too hard onto the fiber end face. This may damage thesurface.

•Use clean dry compressed air (free of dust, water and oil) to blow away any remains from thefiber end face. Nitrogen gas can also be used.

Never exceed the max. ratings of the optical input power.

SHF 11121A – V001 – 25/Oct/2007

SHF reserves the right to change specifications and design without notice

Page 3/8

Specifications – SHF 11121A
Parameter

UnitMin.

Typ.

Max.

Comment

Optical Data Input
Optical Input and Output
connectors

FC/PC

Operating bit rate
VCO 1
VCO 2Gbps

Optical insertion lossdBdB111310 nm
1552 nmAbsolute max. optical input
power

dBm

+6+12mean power
peak power

Optical input dynamic range@ 1552 nm

dBm-3+3NRZ, mean power

0.622
1.244
2.488

0.674
1.348
2.696

400

800

39.8
41.6

41.6
43.1

Reference Clock Input
Input Frequency(Bit Rate / 64 mode)(Bit Rate / 32 mode)(Bit Rate / 16 mode)

GHzInput Voltage

mVppConnectorΩ50SMA-female

Clock 1MHz622.08039.81312 Gbps

Clock 2

MHz666.514

42.65692 Gbps

Clock 3

MHz672.163

43.01841 Gbps

Internal Reference ClockSHF 11121A – V001 – 25/Oct/2007

SHF reserves the right to change specifications and design without notice

Page 4/8

Parameter

Unit

Min.

Typ.

Max.

Comment

Clock /4 Output (quarter bit rate)
Output Frequency

GHz

9.95

10.775

Output VoltagemVpp

400

800

ConnectorΩ

50

RMS-Jitter

fs550

SMA- female700

on scope display, measured
with Agilent 86100A with
precision time base,
0 dBm mean input power,
data signal jitter ≤ 1 ps

Half Clock Output (half bit rate)
Output Frequency

GHz19.921.55

Output Voltage

mVpp

500

1000

ConnectorΩ50

RMS-Jitter

fs500

K-female700

on scope display, measured
with Agilent 86100A with
precision time base,
0 dBm mean input power,
data signal jitter ≤ 1 ps

Full Clock Output (optional, full bit rate)
Output Frequency

GHz

39.8

43.1

Output Voltage

mVpp

500

1000

ConnectorΩ

50

RMS-Jitter

fs500

V-female700

on scope display, measured
with Agilent 86100A with
precision time base,
0 dBm mean input power
data signal jitter ≤ 1 ps

240

47… 63HzGeneral Data
Power SupplyVPower Consumption

W20Weightkg

3.8

Dimensions (WxHxD)

mmOperating temperature°C

1035

Storage temperature°C-2070

Network Connection

Mbps

SHF 11121A – V001 – 25/Oct/2007

90230 V235 x 110 x 355

10 / 100

Ethernet, RJ-45
connector

SHF reserves the right to change specifications and design without notice

Page 5/8

Test Results
Typical clock output signals, 0 dBm optical input power, PRBS 231-1
39.813 Gbps with Internal Reference 1

Data In @ 39.813 Gbps

Clk/4 Out @ 39.813 Gbps

Clk/2 Out @ 39.813 Gbps

Clk Out @ 39.813 Gbps

SHF 11121A – V001 – 25/Oct/2007

SHF reserves the right to change specifications and design without notice

Page 6/8

42.656 Gbps with Internal Reference 2

Data In @ 42.656 Gbps

Clk/4 Out @ 42.656 Gbps

Clk/2 Out @ 42.656 Gbps

Clk Out @ 42.656 Gbps

SHF 11121A – V001 – 25/Oct/2007

SHF reserves the right to change specifications and design without notice

Page 7/8

43.018 Gbps with Internal Reference 3

Data In @ 43.018 Gbps

Clk/4 Out @ 43.018 Gbps

Clk/2 Out @ 43.018 Gbps

Clk Out @ 43.018 Gbps

SHF 11121A – V001 – 25/Oct/2007

SHF reserves the right to change specifications and design without notice

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