MAX15031EVKIT [MAXIM]

Demonstrates APD Fast Current Limit;


型号：	MAX15031EVKIT
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Demonstrates APD Fast Current Limit 光电二极管
文件：	总5页 (文件大小：133K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-4376; Rev 0; 11/08

MAX15031 Evaluation Kit

Evluates:MAX5031

General Description

Features

♦ Tiny 8mm x 18mm Circuit Footprint

♦ 2.9V to 5.5V Wide Supply Voltage Range

♦ 70V Output Voltage (Approximate)

♦ 0 to 4mA Output Current

The MAX15031 evaluation kit (EV kit) demonstrates the

MAX15031 APD biasing pulse-width modulation (PWM)

step-up DC-DC converter with an internal power switch,

current monitor, and adjustable current limiting. The

step-up converter switches at 400kHz. The EV kit oper-

ates from a DC supply voltage of 2.9V to 5.5V and is

configured to deliver approximately 70V and 0 to 4mA

of current at the output. The output voltage can be con-

figured from VIN + 1V to 76V by replacing a resistor or

adjusting the CNTRL voltage. The EV kit demonstrates

the MAX15031 APD fast current-limit, undervoltage

lockout (UVLO), and thermal shutdown features.

♦ Demonstrates APD Fast Current Limit

♦ Demonstrates Undervoltage Lockout

♦ Demonstrates Thermal Shutdown Feature

♦ MOUT Output Overvoltage Protection Through

Clamping Circuit

♦ Lead(Pb)-Free and RoHS Compliant

♦ Fully Assembled and Tested

The actual converter circuit’s PCB footprint is 8mm x

18mm as required in BPON (broadband passive optical

network) and GPON (gigabit passive optical network)

applications and demonstrates the MAX15031’s small,

16-pin TQFN package with exposed pad. The EV kit

also features an APD input load simulator circuit for cur-

rent monitoring and step-response measurements.

Ordering Information

PART

TYPE

MAX15031EVKIT+

EV Kit

WARNING: Voltages exceeding 42V may exist on

the VOUT, APD, MOUT, and PGND PCB pads.

+Denotes lead(Pb)-free and RoHS compliant.

Component List

DESIGNATION QTY

DESCRIPTION

DESIGNATION QTY

DESCRIPTION

1µF 10ꢀ, 10V X5R ceramic

capacitor (0402)

Murata GRM155R61A105K

JU2

3-pin header

4.7µH, 1.5A inductor

Coilcraft ME3220-472MLB

0.01µF 10ꢀ, 25V X7R ceramic

capacitor (0402)

Murata GRM155R71E103K

100V 1.5A n-channel MOSFET (SOT23)

Vishay Si2328DS-T1-E3

(Top Mark: CHV)

0.1µF 10ꢀ, 16V X7R ceramic

capacitors (0402)

Murata GRM155R71C104K

348kΩ 1ꢀ resistor (0603)

6.34kΩ 1ꢀ resistor (0402)

10kΩ 1ꢀ resistors (0402)

2.87kΩ 1ꢀ resistor (0402)

10kΩ 1ꢀ resistor (0805)

10kΩ 1ꢀ resistor (1206)

2kΩ 1ꢀ resistor (0805)

100Ω 1ꢀ resistor (0402)

PC mini red test points

C3, C8

C4, C5

R3, R6

0.1µF 10ꢀ, 100V X7R ceramic

capacitors (0805)

AVX 08051C104KAT

0.01µF 10ꢀ, 100V X7R ceramic

capacitor (0805)

Murata GRM21BR72A103K

R10

Not installed, ceramic capacitor (0402)

TP1, TP2, TP4

TP3, TP6

TP5

10µF 10ꢀ, 10V X5R ceramic

capacitor (0805)

Murata GRM219R61A106K

PC mini black test points

PC mini yellow test point

100V, 150mA Schottky diode (SOD123)

Diodes, Inc. BAT46W-7-F

(Top Mark: L6)

APD boost converter (16 TQFN-EP*)

Maxim MAX15031ATE+

—

Shunts ( JU1, JU2)

JU1

2-pin header

—

PCB: MAX15031 Evaluation Kit+

*EP = Exposed pad.

________________________________________________________________ Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

MAX15031 Evaluation Kit

Component Suppliers

SUPPLIER

AVX Corporation

PHONE

WEBSITE

www.avxcorp.com

843-946-0238

847-639-6400

805-446-4800

770-436-1300

402-563-6866

Coilcraft, Inc.

www.coilcraft.com

Diodes, Inc.

www.diodes.com

Murata Electronics North America, Inc.

Vishay

www.murata-northamerica.com

www.vishay.com

Note: Indicate that you are using the MAX15031 when contacting these component suppliers.

current-limiting circuit features. The circuit’s PWM

step-up DC-DC converter is designed for APD bias-

ing, switches at 400kHz, and is configured to deliver

approximately 70V and 0 to 4mA of current to the APD

output. The output voltage can be reconfigured from

VIN + 1V to 76V by replacing resistor R1 or adjusting

the CNTRL voltage. The EV kit demonstrates the

MAX15031’s APD fast current-limit, undervoltage lock-

out (UVLO), and thermal shutdown features.

Quick Start

Required Equipment

Before beginning, the following equipment is needed:

•

MAX15031 EV kit

2.9V to 5.5V, 1A DC power supply

0 to 5mA adjustable load rated for at least 76V

Digital multimeter (DMM)

Evluates:MAX5031

The converter circuit’s PCB footprint is 8mm x 18mm.

The EV kit operates from a DC supply voltage of 2.9V to

5.5V and provides up to 4mA at the APD output.

The EV kit’s APD load simulator circuit is used for cur-

rent monitoring and step-response measurements. The

circuit is comprised of MOSFET N1, resistors R7, R8,

R9, and test points TP1, TP2, and TP3 (SGND). Test

point TP4 provides access to the MAX15031 BIAS

signal. Voltages exceeding 42V may exist on TP4.

Additionally, bulk capacitor C9 is provided in case long

connecting cables are used to power the EV kit during

lab evaluation. Capacitor C9 is not required in a typical

design.

WARNING: Voltages exceeding 42V may exist on

the VOUT, APD, MOUT, and PGND PCB pads.

Procedure

The MAX15031 EV kit is fully assembled and tested.

Follow the steps below to verify board operation.

Caution: Do not turn on the power supply until all

connections are completed.

1) Verify that a shunt is installed on jumper JU1 (70V

output).

2) Verify that a shunt is installed on pins 1-2 of jumper

JU2 (enabled).

3) Connect the adjustable load to the APD and the

SGND pads.

SHDN and Enable

The MAX15031 EV kit features a jumper to enable and

disable U1. Jumper JU2 will disable the EV kit when the

shunt is installed on pins 2-3. Installing the shunt on

pins 1-2 enables the EV kit. Refer to the Shutdown

(SHDN) section in the MAX15031 IC data sheet for

information. See Table 1 for jumper JU2 settings.

4) Connect the power supply to the VIN pad and the

power-supply ground to the PGND pad.

5) Connect the DMM across the APD and SGND PCB

pads.

6) Turn on the power supply and set it to 3.3V.

7) Verify that the DMM reads approximately 70V.

Table 1. SHDN and Enable (Jumper JU2)

Detailed Description of Hardware

The MAX15031 evaluation kit (EV kit) demonstrates the

MAX15031 in a small, 16-pin TQFN package with

internal power switch, current monitor, and adjustable

SHUNT

POSITION

EV KIT

OPERATION

SHDN PIN

1-2

2-3

Connected to VIN

Enabled

Disabled

Connected to SGND

_______________________________________________________________________________________

MAX15031 Evaluation Kit

Evluates:MAX5031

Additionally, resistors R8 and R9 set the APD load simu-

lator circuit’s current for current-monitor step-response

measurements. Apply a 0 to 11V square-wave signal to

the APD_DRV pad to simulate a 0 to 4mA load. Use test

points TP1 or TP2 to measure the APD load current and

TP3 as the SGND. Refer to the Monitor Current Limit

(RLIM) section in the MAX15031 IC data sheet for addi-

tional information on the MOUT features.

Output-Voltage Programmability

The MAX15031 EV kit features a jumper to set the

VOUT/APD voltage programmability. The output voltage

(VOUT/APD) is programmed by connecting an external

reference voltage source to the CNTRL and SGND PCB

pads. Remove the shunt at jumper JU1 to use the pro-

grammability feature and apply a reference voltage

< 1.25V to the CNTRL pad. When the voltage applied to

the CNTRL pad is > 1.5V, the MAX15031 internal refer-

ence is used. See Table 2 for jumper JU1 settings.

Clamp Input (CLAMP)

The CLAMP input PCB pad is used for voltage clamp-

ing the MOUT pin. Capacitor C6 provides filtering to

the clamp voltage signal. The MAX15031 EV kit is

capable of clamping MOUT voltages between 0.6V to

76V (typ). To clamp MOUT in the range of 0.6V to 4.3V,

apply a voltage between 0 and 3.7V (typ) to the

CLAMP and SGND PCB pads. Refer to the Clamping

the Monitor Output Voltage (CLAMP) section in the

MAX15031 IC data sheet for additional information on

the CLAMP features.

Table 2. Output-Voltage Programming

(Jumper JU1)

SHUNT

POSITION

CNTRL

OUTPUT-VOLTAGE

PROGRAMMING

Connected Fixed output voltage: Internal

to VIN reference voltage used

Installed

Connected Programmable output voltage:

to external Apply an external reference voltage

Not

installed

Fast Current-Limit Threshold

and ILIM Output

Resistor R5 sets the MAX15031 APD fast current-limit

threshold to 4.3mA. To reconfigure the circuit for anoth-

er current-limit threshold, replace resistor R5 and use

the following equation to calculate a new value for the

desired current:

reference

(< 1.25V) at CNTRL PCB pad

Fixed output voltage: Apply an

external reference voltage (> 1.5V*)

at CNTRL PCB pad; internal

reference voltage used

Connected

to external

reference

Not

installed

*Apply a voltage exceeding 1.5V to use the MAX15031 internal

reference. The voltage should be in the range of 1.5V to VIN

voltage. Refer to the Adjusting the Boost Converter Output

Voltage (FB/CNTRL) section in the MAX15031 IC data sheet for

information.

10 ×1.245V

R5(kΩ) =

(mA)

LIMIT

The output voltage at VOUT is set by resistors R1 and

R2 to 70V when jumper JU1 is installed. To reconfigure

the output for a different voltage (VIN + 1V to 76V),

select a new surface-mount 0603 resistor for R1. Refer

to the Setting the Output Voltage section in the

MAX15031 IC data sheet for selecting the R1 value.

where I

liamps.

is the desired DC load current in mil-

LIMIT

The ILIM open-drain signal is available at the ILIM PCB

pad. Resistor R6 pulls up the ILIM pin to VIN; when low,

the MAX15031 is in current limit. To interface with a

microcontroller, connect to the ILIM PCB and SGND

pads. Refer to the Monitor Current Limit (RLIM) section in

the MAX15031 IC data sheet for additional information

on the ILIM feature.

Current-Monitor Output (MOUT)

and APD Load Simulator

The MOUT PCB pad provides a current-monitor output

that sources a current 1/10th the APD current. An RC

network comprised of resistor R3 and capacitor C7

provide a filter to the MOUT signal. Capacitor C7 is not

required in a typical design.

_______________________________________________________________________________________

MAX15031 Evaluation Kit

Evluates:MAX5031

Figure 1. MAX15031 EV Kit Schematic

_______________________________________________________________________________________

MAX15031 Evaluation Kit

Evluates:MAX5031

Figure 2. MAX15031 EV Kit Component Placement Guide—

Component Side

Figure 3. MAX15031 EV Kit PCB Layout—Component Side

Figure 4. MAX15031 EV Kit PCB 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 to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5

is a registered trademark of Maxim Integrated Products, Inc.

MAX15031EVKIT [MAXIM]

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