MAX3738EVKIT [MAXIM]

Evaluation Kit for the MAX3738 ; 评估板MAX3738\n


型号：	MAX3738EVKIT
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Evaluation Kit for the MAX3738 评估板MAX3738\n
文件：	总11页 (文件大小：334K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-3193; Rev 0, 2/04

MAX3738 Evaluation Kit

_______________ General Description

________________________ Features

The MAX3738 evaluation kit (EV kit) is an assembled

demonstration board that provides complete optical and

electrical evaluation of the MAX3738.

Fully Assembled and Tested

Single +3.3V Power Supply Operation

AC-Coupling Provided On-Board

Allows Optical and Electrical Evaluation

The EV kit is composed of two independent sections, one

optical and one electrical, on the PC board. The output of

the electrical evaluation section is interfaced to an SMP

connector that can be connected to a 50Ω terminated

oscilloscope. The output of the optical evaluation section

is configured for attachment to a laser/monitor diode.

_______________Ordering Information

PART

MAX3738EVKIT

TEMP RANGE

-40°C to +85°C

IC-PACKAGE

24 Thin QFN

________________________________________Electrical Evaluation Component List

DESIGNATION

QTY

DESCRIPTION

DESIGNATION

QTY

DESCRIPTION

C1, C2, C17,

1.0µH inductor (1008LS)

Coilcraft 1008CS-122XKBC

MOSFET (SOT23)

0.1µF 10% ceramic

L2, L5

C19,

capacitors (0402)

C39, C41

C3, C6, C14,

C16

C7, C9, C11,

C32

0.01µF 10% ceramic

Fairchild FDN306P

capacitors (0402)

NPN transistor (SOT23)

Zetex FMMT491A

0.01µF 10% ceramic

capacitors (0201)

PNP transistor (SOT23)

Zetex FMMT591A

0.5pF 10% ceramic

capacitor (0201)

C10

C4, C5, C12

C18, C36

R23-R25, R28-

R34, R41, R42,

R49

LED, red T1 package

470pF 10% ceramic

capacitors (0402)

—

Not installed

10µF 10% tantalum

capacitor, case B

R11

4.99Ω 1% resistor (0402)

30.1Ω 1% resistors (0402)

75Ω 1% resistor (0402)

392Ω 1% resistor (0402)

511Ω 1% resistor (0402)

332Ω 1% resistor (0402)

3.32kΩ 1% resistor (0402)

4.7kΩ 1% resistor (0402)

100Ω 1% resistor (0402)

R12, R13, R14

R50

SMP connector,

Tensolite P698-2CC

SMA connectors, round,

Johnson 142-0701-801

R18

J1, J2

R10

JU1, JU8, JU11,

JU14, JU15,

JU17-JU19

R58

2-pin headers, 0.1in centers

R61

R8, R9

R1-R3, R5, R6

JU12, JU13

4-pin headers, 0.1in centers

3-pin headers, 0.1in centers

JU3-JU5

J8, J13, J14,

TP2-TP4, TP6,

TP7, TP9,

20kΩ Variable Resistor

R26

(3296W)

50kΩ Variable Resistor

R4, R7, R27

Test Points

(3296W)

TP10, TP12,

TP14-TP17

__________________________________________Maxim Integrated Products 1

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct!

at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

MAX3738 Evaluation Kit

_______________________________Electrical Evaluation Component List (cont.)

DESIGNATION

QTY

DESCRIPTION

MAX495ESA (8 SO)

MAX3738ETJ

(24 Thin QFN)

None

Shunts

MAX3738 EV board

MAX3738 data Sheet

_________________________________________Optical Evaluation Component List

DESIGNATION QTY

DESCRIPTION

DESIGNATION

QTY

DESCRIPTION

Not installed

C23, C25, C28,

R35-R38, R40,

R43-R47

R39*, R48

R54

—

0.01µF 10% ceramic

C30, C31, C33,

C40

capacitors (0402)

49.9Ω 1% resistor (0402)

10Ω 1% resistor (0402)

15Ω 1% resistor (0402)

511Ω 1% resistor (0402)

4.7kΩ 1% resistor (0402)

0.01µF 10% ceramic

C26, C29

capacitors (0603)

R56

8.2pF 10% ceramic

capacitor (0402)

R59

C24*

R60

470pF 10% ceramic

capacitors (0402)

3.32kΩ 5% resistor

C27, C34, C35

R62

R65

(0402)

C20, C22, C37,

C38

0.1µF 10% ceramic

332Ω 5% resistor (0402)

capacitors (0402)

R63, R64, R68

R51-R53

R55

100Ω 5% resistor (0402)

10µF 10% tantalum

capacitor, case B

C21

—

Not installed

—

Open, user-supplied laser

LED, red T1 package

SMA connectors, round,

Johnson 142-0701-801

20kΩ variable resistors

Bourns 3296W

J4, J5

50kΩ variable resistors

Bourns 3296W

R57

JU16, JU20,

JU30

2-pin headers, 0.1in centers

J3, J6, TP1, TP5,

TP8, TP11, TP13,

TP19, TP20,

TP25-TPT27

None

MAX3738EGJ (32 QFN)

Ferrite bead (0603)

Murata BLM18GA601SN1

Test points

1.0µH inductor (1008CS)

Coilcraft 1008CS-122XKBC

MOSFET (SOT23)

Shunt

Fairchild FDN306P

None

MAX3738 EV board

MAX3738 data sheet

None

NPN transistor (SOT23)

Zetex FMMT491A

*These components are part of the compensation network, which can reduce overshoot and ringing. Ringing due to

parasitic series inductance of the laser may be eliminated with R39 and C24. Starting values for most coaxial lasers is

R39 = 49.9Ω in series with C24 = 8.2pF. These values should be experimentally adjusted until the output waveform is

optimised.

______________ Component Suppliers

Note: Please indicate that you are using the MAX3738 when

SUPPLIER

AVX

PHONE

FAX

contacting these component suppliers.

803-946-0690

847-639-6400

814-237-1431

516-543-7100

803-626-3123

847-639-1469

814-238-0490

516-864-7630

Coilcraft

Murata

Zetex

2 _________________________________________________________________________________________

MAX3738 Evaluation Kit

11) Attach a high-speed oscilloscope with a 50Ω input to

__________________________Quick Start

the SMP connector J7 (OUT+).

Electrical Evaluation

In the electrical configuration, an automatic power control

(APC) test circuit is included to emulate a semiconductor

laser with a monitor photodiode. Monitor diode current is

provided by transistor Q2, which is controlled by an

operational amplifier (U2). The APC test circuit consisting

of U2 and Q2 applies the simulated monitor diode current

(the DC laser current divided by a factor of 80) to the MD

pin of the MAX3738.

Note: J7 has a DC voltage of approximately V_CC/2

and can have voltage swings greater than 1V. An

attenuator might be needed to make the signal

compatible with the oscilloscope.

12) Connect a +3.3V supply between V_CCand GND

Adjust the power supply until the voltage between

TP12 and ground is +3.3V.

13) Adjust R25 (R_APCSET) until the desired laser bias

current is achieved.

1) Place shunts on JU1, JU3, JU4, JU5, JU12, JU13,

and JU19 (Refer to Table 1 for details).

V_TP7- V_TP6

I_BIAS

2) If the EV kit is to be used without the optional

shutdown transistor (Q3), place a shunt on JU11.

4.9Ω

14) The MD and BIAS currents can be monitored at TP2

(V_{PC_MON}) and TP3 (V_{BC_MON}) using the equation

below:

3) Remove the shunt from JU15 to use the filter

inductor.

4) Connect TX_DISABLE to GND with JU1 to enable

the outputs.

V_{PC_MON}

R_{PC_MON}

I_MD

5) Standard electrical tests have bias and modulation

current separated. Check that R11 (between TP6

and TP7) is installed.

80× V_{BC_MON}

I_BIAS

Note: When performing the following resistance

checks, manually set the ohmmeter to a high range

to avoid forward biasing the on-chip ESD protection

diodes.

R_{BC_MON}

15) Adjust R27 until the desired laser modulation current

6) Adjust R27, the R_MODSETpotentiometer, for 25kΩ

is achieved. Measure I_MODwith the oscilloscope at J7

by;

resistance between TP10 and ground.

7) Adjust R26, the R_APCSETpotentiometer, for 25kΩ

resistance between TP9 and ground.

Signal Amplitude(V_P-P)

I_MOD

8) Adjust R4, the R_{PC_MON}potentiometer, to set the

maximum monitor diode current (I_MDMAX, see below).

R_{PC_MON}can be measured from TP1 to ground.

Connect the R_{PC_MON}using JU3.

15Ω

V_REF

I_MDMAX

R_{PC_MON}

Optical Evaluation

9) Adjust R7, the R_{BC_MON}potentiometer, to set the

maximum bias current (I_BIASMAX, see below). R_{BC_MON}

can be measured from TP2 to ground. Connect the

R_{BC_MON}using JU4.

For optical evaluation of the MAX3738, configure the

evaluation kit as follows:

1) Remove shunt JU16 to use the filter inductor.

80× V_REF

I_BIASMAX

R_{BC_MON}

2) If the EV kit is to be used without the optional

shutdown transistor (Q4), place a shunt on JU20.

3) To enable the outputs, connect TX_DISABLE to GND

by placing a shunt on JU30.

4) The EV kit is designed to allow connection of a

variety of possible laser/monitor diode pin

configurations. Connect a TO-header style laser with

monitor diode (Figure 1) as follows:

10) Apply a 2.7Gbps differential input signal (200mV_P-Pto

2400mV_P-P) between SMA connectors J1 and J2 (IN+

and IN-).

________________________________________________________ 3

MAX3738 Evaluation Kit

•

Keeping its leads as short as possible, connect

the laser diode to two of the three pads in the

cutout portion on the top (component) side of the

PC board. Solder the laser diode cathode to the

center pad, and solder the anode to either of the

other two pads (they are both connected to V_CC

through the shutdown transistor (Q4)).

80× V_REF

I_BIASMAX

R_{BC_MON}

9) Apply a 2.7Gbps differential input signal (200mV_P-Pto

2400mV_P-P) between SMA connectors J5 and J4 (IN+

and IN-).

•

Connect the monitor photodiode to two of the

five pads on the bottom (solder) side of the PC

board, directly below the laser diode pads.

Connect the anode and cathode of the

photodiode as shown in figure 1.

10) Attach the laser diode fiber connector to an

optical/electrical converter.

Note: When performing the following resistance

checks, manually set the ohmmeter to a high range

to avoid forward biasing the on-chip ESD protection

diodes.

11) Connect a +3.3V supply between J3 (V_CC) and J6

(GND). Adjust the power supply until the voltage

between TP15 and ground is +3.3V.

12) Adjust R55 (R_APCSET) until the desired average optical

power is achieved.

5) Adjust R57, the R_MODSETpotentiometer, for maximum

resistance (≈50kΩ) between TP19 and ground. This

sets the modulation current to a low value (<10mA).

(Refer to the Design Procedure section of the

MAX3738 data sheet.)

13) The MD, MOD and BIAS currents can be monitored

at TP27 (V_{PC_MON}) and TP26 (V_{BC_MON}) using the

equations below:

V_{PC_MON}

R_{PC_MON}

6) Adjust R55, the R_APCSETpotentiometer, for maximum

resistance (≈50kΩ) between TP20 and ground. This

sets the photodiode current to a low value (<18µA).

(Refer to the Design Procedure section of the

MAX3738 data sheet.)

I_MD

80× V_{BC_MON}

I_BIAS

WARNING: Consult your laser data sheet to ensure

that 18µA of photodiode current and 10mA of

modulation current does not correspond to excessive

laser power.

R_{BC_MON}

Note: If the voltage at TP26 or TP27 exceeds 1.38V,

7) Install R64, the R_{PC_MON}resistor, to set the maximum

monitor diode current (I_MDMAX, see below).

the TX_FAULT signal will be asserted and latched.

14) Adjust R57 (R_MODSET

) until the desired optical

amplitude is achieved. Optical amplitude can be

observed on an oscilloscope connected to an

optical/electrical converter. Laser overshoot and

ringing can be improved by appropriate selection of

R39 and C24, as described in the Design Procedure

section of the MAX3738 data sheet.

V_REF

I_MDMAX

R_{PC_MON}

8) Install R63, the R_{BC_MON}resistor, to set the maximum

bias current (I_BIASMAX, see below).

4 _________________________________________________________________________________________

MAX3738 Evaluation Kit

Table 1. Adjustment and Control Descriptions (see Quick Start first)

COMPONENT

NAME

FUNCTION

OPTICAL

ELECTRICAL

LED is illuminated when a fault condition has occurred

(Refer to the Detailed Description section of the

MAX3735 data sheet).

Fault

Indicator

Placing a shunt on JU15 or JU16 removes the inductor

from the filter networks by shorting the inductor lead

together. Remove shunts for normal operation.

JU16

JU15

—

Placing a shunt on JU13 connects the MODSET pin of

the MAX3738 to the R_MODSETpotentiometer. Select a

fixed resistor value when testing over temperature.

—

JU30

—

JU13

JU1

—

TX_DISABLE

—

Enables/disables the output currents. Active low (shunt

across JU1 or JU30 to enable output currents).

Placing a shunt on JU12connects the APCSET pin of

the MAX3738 to the R_APCSETpotentiometer. Select a

fixed resistor value when testing over temperature.

JU12

Installing a jumper on JU11 or JU20 disables the

optional shutdown transistors.

JU20

JU11

—

R40, R57

R45, R55

R27, R29, R30

R23, R24, R26

R_MODSET

R_APCSET

Adjusts the laser modulation current

Adjusts the monitor diode current level to be maintained

by the APC loop

Sets the K factor compensation of the modulation

current. Leave open to make modulation current

independent of bias current.

R51, R38

R52, R37

R53, R36

R31, JU14

R32, JU18

R33, JU17

R_MODBCOMP

Sets the threshold temperature above which modulation

current increases with temperature.

R_{TH_TEMP}

Sets the temperature coefficient of the modulation

current. Leave open to make modulation current

independent of temperature.

R_MODTCOMP

________________________________________________________ 5

MAX3738 Evaluation Kit

CONFIGURATION 1

CONFIGURATION 2

TOP OF PC

BOARD

TOP OF PC

BOARD

R19

V_CC

T0-46 CAN

LASER/PHOTODIODE

PAIR

LASER/PHOTODIODE

PAIR

V_CC

SOLDER

BRIDGES

SOLDER

BRIDGES

TO MD

BOTTOM OF PC

BOARD

BOTTOM OF PC

BOARD

CONFIGURATION 3

CONFIGURATION 4

TOP OF PC

BOARD

TOP OF PC

BOARD

R19

V_CC

T0-46 CAN

LASER/PHOTODIODE

PAIR

LASER/PHOTODIODE

PAIR

V_CC

SOLDER

BRIDGES

SOLDER

BRIDGES

TO MD

BOTTOM OF PC

BOARD

BOTTOM OF PC

BOARD

Figure 1. Attachment of Laser Diode/Monitor Diode to the MAX3738 EV Kit

6 _________________________________________________________________________________________

MAX3738 Evaluation Kit

1 T L I F A P C

2 T L I F A P C

S E T A P C

D G N

T L U A F _ T X

G N

S D E O T M

N W D O H S U T

N O M _ B C

P M C O D O B M

P M E T _ T H

N O M _ P C

Figure 2. MAX3738 EV Kit Schematic—Electrical Configuration

________________________________________________________ 7

MAX3738 Evaluation Kit

1 T L I F A P C

G N

T L I F A P C

L U A F _ T X

S E T A P C

G N

N W D O H U S T

S E D T O M

N W D O H S U T

N O M _ B C

P M C O D O B M

P M E T _ T H

N O M _ P C

Figure 3. MAX3738 EV Kit Schematic—Optical Configuration

8 ________________________________________________________________________________________

MAX3738 Evaluation Kit

Figure 4. MAX3738 EV Kit PC Component Placement

Guide-Component Side

Figure 5: MAX3738 EV Kit PC Component Placement

Guide-Solder Side

________________________________________________________ 9

MAX3738 Evaluation Kit

Figure 6. MAX3738 EV Kit PC Board Layout -

Component Side

Figure 7: MAX3738 EV Kit PC Board Layout – Ground

Plane

10 ________________________________________________________________________________________

MAX3738 Evaluation Kit

Figure 8: MAX3738 EV Kit PC Board Layout – Power

Plane

Figure 9: MAX3738 EV Kit PC Board Layout – Solder

Side

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim

reserves the right o change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________ 11

 2004 Maxim Integrated Products Printed USA

is a registered trademark of Maxim Integrated Products

MAX3738EVKIT [MAXIM]

相关型号：

MAX3738_08

MAX3738_11

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MAX3740AETG

MAX3740AETG+

MAX3740AETG+T

MAX3740AETG-T

MAX3740A_10

MAX3740ETG

MAX3740ETG+

MAX3740ETG+T