MAX3949 Evaluation Kit Evaluates: MAX3949MAX3949 Evaluation Kit Evaluates: MAX3949 Component List General Description. The MAX3949 evaluation kit (EV kit) is a fully test-ed and assembled

MAX3949 Evaluation Kit Evaluates: MAX3949

Component List

General DescriptionThe MAX3949 evaluation kit (EV kit) is a fully test-ed and assembled demonstration board that provides optical evaluation of the MAX3949 AC-coupled, 1Gbps to 11.3Gbps laser driver. The controlling software communi-cates with the EV kit through the USB port and provides simplified control of all functions of the IC. The EV kit can be fully powered by the USB port or the user can choose to power the IC by a single external 3.3V supply, while the USB port supplies the on-board microcontroller. The flex-cable connection on the evaluation board allows attach-ment of lasers incorporating flex cables.

Features DrivesDifferentiallyConnectedLasers SoftwareControloftheIC PowerSuppliedthroughtheUSBorExternal

Connection ProvenPCBLayout FullyAssembledandTested

19-6533; Rev 0; 12/12

Ordering Information appears at end of data sheet.

*EP = Exposed pad.

DESIGNATION QTY DESCRIPTIONC1, C3–C5,

C8, C16 6 0.01µF±10%ceramiccapacitors(0402)

C2, C10, C14, C28 0 Not installed, ceramic capacitors

(0201)

C6, C9 0 0.5pF±0.1pFceramiccapacitors(0402)

C7, C12, C24, C29, C33 5 0.1µF±20%ceramiccapacitors

(0204)C11, C13, C15 3 10µF±10%ceramiccapacitors(0805)

C21, C22 2 33pF±10%ceramiccapacitors(0402)C25–C27, C49,

C52 5 0.1µF±10%ceramiccapacitors(0402)

C34, C55 2 1µF±10%ceramiccapacitors(0603)

C35, C37, C38 3 4.7µF±10%ceramiccapacitors(0805)

D6 1 GreenLEDJ1, J2 2 Edge-mount SMA connectors

J3,J4,TP1–TP4,TP6–TP15 16 Test points

J5–J7, J9, J10 5 2-pin headers, 0.1in centersJ8 1 Mini-USB, type B connector

L1 1 22µF,±20%inductorTaiyo Yuden CBC3225T220M

L2,L3 2 18nH±2%inductors(0402)

L4,L6 2 Ferritebeads(0402)MurataBLM15GG471

DESIGNATION QTY DESCRIPTIONL5,L10,L14 3 10µH±10%inductors(0603)

R1 1 1.00kΩ±1%resistor(0402)R2, R7, R8, R12 0 Not installed, resistors (0201)

R3 1 680Ω±5%resistor(0402)R4, R31, R51,

R53 4 10kΩ±5%resistors(0402)

R5, R6 2 20Ω±5%resistors(0402)R10 1 100Ω±5%resistor(0402)

R15, R50 2 4.7kΩ±5%resistors(0402)R18, R52, R55,

R66, R73 5 51Ω±5%resistors(0402)

R24 1 1.5kΩ±5%resistor(0402)SW1 1 SPDTswitch

U1 11Gbpsto11.3Gbps,SFP+laserdriver(16TQFN-EP*)MaximMAX3949ETE+

U2 1 Low-noiseLDOregulator(8TDFN)MaximMAX8902AATA+

U6 0 Notinstalled,user-suppliedTOSA

U10 1 Microcontroller(28SO)MicrochipPIC16C745-I/SO

Y2 1 6MHz crystalECSInc.ECS-60-32-5PXDN

— 1 PCB:MAX3949EVALUATIONBOARDREVA

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www.maximintegrated.com

Quick StartRequired Equipment MAX3949EVkit Windows® PC OscilloscopeNote: In the following sections, software-related items are identified by bold text. Text in bold and underlined refers to items from the Windows operating system.

Procedure1) SolderalasertoU6.SeeFigure1formoreinforma-

tion about the laser connection.2) Set SW1 to the desired power-supply option (USB or

external supply).3) If an external power supply is used, set the voltage

to 3.3V, the current limit to 300mA, and connect the supply to the board.

4) Get the latest version of the EV kit software (MAX3949Rev1.ZIP) by contacting Maxim custom-er support at support.maximintegrated.com. After receiving the file, unzip it to a local folder and run the installation executable (setup.EXE). Installation requires administrative rights and can also require Internet access to download the nec essary drivers.

5) After installation is complete, follow this path to start theprogram:Start → All Programs → Maxim Integrated Products → MAX3949 EV Kit GUI.

6) Connect the computer to the EV kit with a USB cable (A-male to Mini-B-Male). LED D6 should illuminate,

indicating thatUSBpower is detected.Press theUSB Connect button in the software to initiate communication to the EV kit. The Status indicator turns green when communication is established.

7) Connecta50ΩsourcetoTIN-andTIN+(J1andJ2).Set the source differential amplitude to 500mVP-P.

8) Connect the output from the TOSA to an opticalreceiver (optical-to-electrical converter or optical input head on an oscilloscope).

9) Alldevicecontrolsareavailableinthesoftware.Faultand warning indicators are displayed on the right side of the graphical user interface (GUI) window. When a hard fault has occurred, the part goes into latched shutdown. The source of the fault should be removed and the DISABLE checkbox should be toggled to reset the part.

10) The registers contain a default setting and can be read using the Tx Read Allbutton.Fordetailedregis-ter functions, refer to the MAX3949 IC data sheet.

11) To enable the part, the DISABLE checkbox should be toggled (check then uncheck) and the TX Enable checkbox should be checked. After doing this, press the TX Read All button twice and check to see if any faults are indicated. If everything is set up properly, all fault indicators should be green.

12) The Tx De-emphasis Control can be used to adjust the eye diagram. After choosing a new setting, press the Tx De-emphasis Control LOAD button followed by the IMod LOAD button. This loads the new preem-phasis setting to the modulation current driver.

Detailed Description of SoftwareGraphical User Interface (GUI)TheMAX3949EVkitGUIconsistsofthreemainblocks:bias and modulation control, data path adjustments, and fault indicators.

Bias and Modulation ControlForbiasandmodulationcurrenttherearethreecontrols:set current, set maximum, and increment. The left-side data-entry boxes allow the user to write to the SET_IBIAS or SET_IMOD register directly, as long as that value isbelowthevalueloadedintheIBIASMAXandIMODMAXregisters. The middle data-entry boxes allow the user towrite to the IBIASMAXand IMODMAX registers.Theright-side data-entry boxes allow the user to increment or decrement the bias and modulation current registers over a±15LSBrangebywritingtotheBIASINCandMODINCregisters. The appropriate LOAD button must be pressed Figure 1. TOSA Connection

Windows is a registered trademark and registered service mark of Microsoft Corporation.

N.C.

LD C

ATHO

DEGND

LD A

NODE GN

D

N.C.

U6

1

https://support.maximintegrated.com/

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Figure 2. MAX3949 EV Kit Software

to initiate a register write. The READ buttons read and display the values held in the SET_IBIAS/SET_IMOD,IBIASMAX/IMODMAX,andBIASINC/MODINCregisters.

Data Path AdjustmentsThis group box allows control of deemphasis, the input equalization, and data polarity. The Tx De-emphasis Control has a drop-down list with four options for setting theTXDE_MDregister.Whenmanualcontrolisselected,the De-emphasis drop-down list becomes available to write values to the SET_TXDE register. The Tx EQ Control checkboxes lets the user set the two SET_TXEQ bits, checked for a 1 and unchecked for a 0. When the Tx Polaritycheckboxischecked,theTOUT+pinsinkscur-rentwhenTIN+ishigh(typicalsetup).Theoutputpolarityis inverted if the checkbox is left unchecked.

Fault IndicatorsAlong the right-hand side of the GUI are fault indicators that show the status of the TXSTAT1 and TXSTAT2 reg-isters. Hard faults disable the part and require a toggling

of the DISABLE checkbox to restart the part (once the source of the fault has been removed). The hard faults can be masked by checking the appropriate checkbox beside the fault indicator. Soft faults operate as warnings but do not disable the part. Automatic updating of the fault monitors can be enabled by checking the Auto Read Enabled checkbox.

Output NetworkThe output network has multiple components to improve the optical eye diagram. The RC shunts on the laser’s anode and cathode (R7, C10, R2, and C14) affect the S22 of the IC and are placed very close to the output pins, TOUTAandTOUTC.TheRCshuntsneartheTOSA(R12,C2, R8, and C28) help compensate for the mismatch in impedancewhere theTOSAsolders to thePCB.FormanyTOSAs,RCshuntsareonlyneededat theTOSAsideof theconnection.Typically,RCvaluesof82Ωand0.4pFonR8,R12,C28,andC2aregoodstartingvalues.

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Figure 3. MAX3949 EV Kit Schematic

MCLR

RA0

RA1

RA2

RA3

RA4

RA5

VSS

OSC1

OSC2

RC0

RC1

RC2

VUSB

RB7

RB6

RB5

RB4

RB3

RB2

RB1

RB0

VDD

VSS

RC7

RC6

D+ D-

U10

R1851Ω

R55

51Ω

R5251Ω

R6651Ω

R7351Ω

J7 J6 J5 J9 J10R51

10kΩ

R50

4.7kΩ

R5310kΩ

R154.7kΩ

DISABLE

FAULT

CSEL

SCL

SDA

C52

0.1µF

VCCD

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Y2

C21

33pF

C2233pF

C26

0.1µF

C250.1µF

R24

1.5kΩ

VUSB

C374.7µF

C490.1µF

R3680Ω

D6

L1 22µH

C354.7µF

C38

4.7µF

C27

0.1µF

C341µF

VBUS

D-

D+

NC

GNDJ8

28 27 26 25 24 23 22 21 20 19 18 17 16 15

IN GND

EN

SELA

1 2 3 45678

U2

OUT

BYP

OUTS

SELB

MAX8902

VUSB

5VTP14

C11

10µF

C1310µF

C80.01µF

1 2 3 4 5

L4BLM15GG471VCCD

TP15

VCC

C160.01µF

C1510µF

J43.3V J3

GND

SW1

TP9

TP10

TP12

TP11

TP13

R31

10kΩVUSB

VUSB

C55 1µF

DISABLE

VCC

VSEL

FAULT

VCCT

TOUTA

TOUTC

VCCT

BMON

TIN-

TIN+

VCC

SCL

SDA

CSEL

BIAS

C4

0.01µF

C50.01µF

C1

0.01µF

C30.01µF

J1TIN-

J2 TIN+ VCC

VCC

DISABLE

TP1

DISABLE TP2

VSEL

R4

10kΩ

TP3

TX_FAULT

FAULT

TP4

BMON

R1

1.00kΩ

TP6

SCL

TP7

SDA

TP8

CSEL

SCL

SDA

CSEL

R7

OPEN

R2OPEN

R8OPEN

C28OPEN

VCC

VCC

C33

0.1µF

R620Ω

L10

10µH

L14

10µH

L2 18nH C6

0.5pF

C9

0.5pF

L3 18nHC70.1µF

R5

20Ω

C120.1µF

CASE

LD_ANODE

CASE

LD_CATHODE

1

PD_CATHODE

23

4

NC

56

1615

1413

56

78

1 2 3 4

12 11 10 9

MAX3949

C29

0.1µF

Z0=25Ω

Z0=25Ω

U1

U6

R12

OPENC2

OPEN

C10

OPEN

C14OPEN

R10100Ω

L510µH

L6FerriteBead

C240.1µF

SW1EXT.POWER

USBPOWER

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Figure 4. MAX3949 EV Kit Component Placement Guide—Component Side

3305mil

2870mil

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Figure 5. MAX3949 EV Kit PCB Layout—Top Side

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Figure 6. MAX3949 EV Kit PCB Layout—Ground Plane

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Figure 7. MAX3949 EV Kit PCB Layout—Power Plane

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Figure 8. MAX3949 EV Kit PCB Layout—Solder Side

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Figure 9. MAX3949 EV Kit Component Placement Guide—Solder Side

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#Denotes RoHS compliant.

Ordering InformationPART TITLE

MAX3949EVKIT# EV Kit

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2012 MaximIntegratedProducts,Inc. 12


Revision HistoryREVISIONNUMBER

REVISIONDATE DESCRIPTION PAGES

CHANGED0 12/12 Initial release —

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

Documents

MAX3949 Evaluation Kit Evaluates: MAX3949MAX3949 Evaluation Kit Evaluates: MAX3949 Component List General Description. The MAX3949 evaluation kit (EV kit) is a fully test-ed and assembled