max3949 evaluation kit evaluates: max3949max3949 evaluation kit evaluates: max3949 component list...
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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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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
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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
MAX3949 Evaluation Kit Evaluates: MAX3949
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.