MAX5969AEVKIT# - Maxim Integrated

General Description

The MAX5969A evaluation kit (EV kit) is a fully assembled

and tested surface-mount circuit board featuring the

MAX5969A IEEE 802.3af/at-compliant network powered

device (PD) interface controller and the MAX5974A

inductive-feedback, spread-spectrum, current-mode

PWM controller. The EV kit is designed as a high-perfor-

mance, compact, and cost-efficient solution for a Class

3 (scalable to Class 4) PD used in Power-over-Ethernet

(PoE) applications.

The EV kit demonstrates the full functionality of the

MAX5969A, such as PD detection signature, PD

classification signature, inrush current control, and input

undervoltage lockout (UVLO). The EV kit also features

an isolated 12W, 300kHz switching-frequency, synchro-

nous-rectified flyback DC-DC converter topology, using

the MAX5974A inductive-feedback, current-mode PWM

controller. The EV kit circuit is configured for an output

voltage of +12V and provides up to 1A load current using

primary-side regulation. The surface-mount transformer

provides up to +1500V galvanic isolation for the output.

The EV kit receives power from IEEEM 802.3af/at-compli-

ant power-sourcing equipment (PSE). The PSE provides

the required -36V to -57V DC power over an unshielded

twisted-pair Ethernet network cable to the EV kit’s RJ45

magnetic jack. The EV kit features a 1 x 1Gb Ethernet

RJ45 magnetic jack and two full-bridge diodes for sepa-

rating the DC power provided by an endspan or midspan

Ethernet system.

The EV kit circuit can also be powered by a +36V to

+57V wall adapter power source, applied at the WAD_IN

and WAD_GND PCB pads. When a wall adapter power

source is detected, it always takes precedence over the

PSE source, allowing the wall adapter to power the EV kit.

Warning: The EV kit is designed to operate with high

voltages. Dangerous voltages are present on this EV kit

and on equipment connected to it. Users who power up

this EV kit or the power sources connected to it must be

careful to follow safety procedures appropriately to work

with high-voltage electrical equipment.

Under severe fault or failure conditions, this EV kit may

dissipate large amounts of power, which could result in

the mechanical ejection of a component or of component

debris at high velocity. Operate this kit with care to avoid

possible personal injury.

Features

S IEEE 802.3af/at-Compliant PD Interface Circuit

S -36V to -57V Startup Input Voltage Range

S 92% (typ) Efficiency

S Demonstrates Isolated 12W Flyback DC-DC

Converter

S Isolated +12V Output at 1A

S 300kHz Switching Frequency

S Configurable for Optocoupler Feedback Operation

S Scalable to 12V Class 4 PD

S PD Detection and Configurable Classification

Signatures

S 2-Event Classification or Wall Adapter Detect

Output

S Inrush Current Limit of 135mA (typ)

S Internal UVLO at -35.6V (typ)

S Evaluates Endspan and Midspan Ethernet

Systems

S Simplified Wall Adapter Interface

S Proven PCB Layout

S Fully Assembled and Tested

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

_________________________________________________________________ Maxim Integrated Products 1

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.

19-5194; Rev 0; 10/11

Ordering Information appears at end of data sheet.

IEEE is a registered service mark of the Institute of Electrical

and Electronics Engineers, Inc.

DESIGNATION QTY DESCRIPTION

C1, C21 0Not installed, ceramic capacitors

(0805)

C2, C18 2

0.1FF Q10%, 100V X7R ceramic

capacitors (0805)

TDK C2012X7R2A104K

C3 1

0.022FF Q10%, 25V X7R

ceramic capacitor (0603)

Murata GRM188R71E223K

C4 1

10FF Q10%, 25V X7R ceramic

capacitor (1206)

Taiyo Yuden TMK316B7106K

C5 1

10pF Q5%, 50V C0G ceramic

capacitor (0603)

Murata GRM1885C1H100J

C6, C13, C30 3

1FF Q10%, 100V X7R ceramic

capacitors (1206)

TDK C3216X7R2A105K

C7 1

22FF Q20%, 63V electrolytic

capacitor (6.6mm x 6.6mm)

Panasonic EEEFK1J220XP

C8 1

1000pF Q10%, 1500V X7R

ceramic capacitor (1808)

AVX 1808SC102KAT1A

C9 1

330pF Q5%, 50V C0G ceramic

capacitor (0603)

Murata GRM1885C1H331J

C10 1

47FF Q10%, 16V X5R ceramic

capacitor (1210)

Murata GRM32ER61C476K

C11 1

10FF Q10%, 16V X5R ceramic

capacitor (1206)

Murata GRM31CR61C106KC31K

C12, C17 2

0.1FF Q10%, 50V X7R ceramic

capacitors (0603)

Murata GRM188R71H104K

C14 1

0.01FF Q10%, 25V X7R ceramic

capacitor (0603)

Murata GRM188R71E103K

C15 1

0.047FF, 16V X7R ceramic

capacitor (0402)

Murata GRM155R71E473K

C16 1

100pF, 50V X7R ceramic

capacitor (0402)

Murata GRM1555C1H101J

DESIGNATION QTY DESCRIPTION

C19 1

1000pF, 50V X7R ceramic

capacitor ( 0402)

Murata GRM155R71H102K

C20, C22 2

2200pF, 100V X5R ceramic

capacitors (0603)

Murata GRM188R72A222K

C23 1

2200pF Q20%, 250V AC X7R

ceramic capacitor (2220)

Murata GA355QR7GF222KW0IL

C24–C29 0 Not installed, ceramic capacitors

(0603)

C31 0 Not installed, ceramic capacitor

(1210)

D1, D2 2

100V, 0.8A bridge rectifiers

(miniDIP)

Diodes Inc. HD01-T

D3 1

58V transient-voltage suppressor

(SMB)

Diodes Inc. SMBJ58A-13-F

(Top Mark: NG)

D4 1 100V, 2A Schottky diode (SMB)

Diodes Inc. ES2B-13-F

D5 0 Not installed, zener diode

(SOT23)

D6 1

58V transient-voltage suppressor

(SMA)

Diodes Inc. SMAJ58A-13-F

D7 1 100V, 1A rectifier (SMA)

Diodes Inc. S1B-13-F

D8 1

60V, 500mA Schottky diode

(SOD123)

STMicroelectronics STPS0560

D9 0 Not installed, Schottky diode

(SOD123)

D10 1

100mA, 80V switching diode

(SOD323)

Diodes Inc. 1N4148WS

J1 1 Modular, side-entry, 8-position

jack assembly

L1 1

80V, 2A common-mode choke

TDK ZJYS81R5-2P24 or

Sumida CPFC74NP-4251-T11

L2 1 3.3FH, 2.6A inductor

Cooper Bussmann SD53-3R3-R

_________________________________________________________________ Maxim Integrated Products 2

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Component List

DESIGNATION QTY DESCRIPTION

L3 1

50V, 2A common-mode choke

TDK ZJYS51R5-2P-01 or

Sumida CPFC74NP-PS02H2A20

N1 1

150V, 4.1A n-channel transistor

(8 SO)

Fairchild FDS86242

N2 1

60V, 2.7A n-channel MOSFET

(3 SOT23)

International Rectifier

IRLML0060TRPbF

N3 0 Not installed, MOSFET

(3 SOT23)

Q2 1

30V, 100mA pnp transistor

(SOT23)

Central Semi CMPT3906

(Top Mark: 3L)

R1 1 24.9kI Q1% resistor (0603)

R2 1 68I Q5% resistor (0603)

R3 1 330I Q1% resistor (0603)

R4 1 43.2I Q1% resistor (0805)

R5 1 59kI Q1% resistor (0603)

R6 1 16.9kI Q1% resistor (0603)

R7 1 34kI Q1% resistor (0603)

R8 1 53.6kI Q1% resistor (0603)

R9, R27 2100kI Q1% resistors (0603)

R10 1 2kI Q1% resistor (0603)

R11 1 30.1kI 1% resistor (0603)

R12, R16 210kI Q1% resistors (0603)

R13, R14 210I Q5% resistors (0805)

R15 1 29.4kI Q1% resistor (0603)

R17, R38, R41,

R43, R44, R45,

R47–R54, R56

0Not installed, resistors (0603)

R18 1 4.02kI Q1% resistor (0603)

DESIGNATION QTY DESCRIPTION

R19 1 10I Q5% resistor (0603)

R20, R22, R23,

R24, R40, R55 0Not installed, resistors (0805)

R21, R25 20.43I Q1%, 1/4W resistors

(1206)

R26 1 499I Q5% resistor (0603)

R28 1 49.9kI Q1% resistor (0603)

R29 1 1MI Q5% resistor (0603)

R30–R33 4 75I Q5% resistors (0805)

R35 1 1.5MI Q1% resistor (0603)

R46 1 0I Q5% resistor (0603)

RJ45 1

RJ45 MagJackM 1G Ethernet,

802.3af/at standard

Bel Fuse Inc. 0826-1X1T-GH-F

T1 1

4.0:8.0:3.2:1 flyback transformer

(8 EP10)

Pulse Engineering PA3342NL or

Sumida CEP1311-04367-T204

TP1, VDD 2Small red test points

TP2, VSS 2Small black test points

U1 1

IEEE 802.3af/at-compliant PD

interface (10 TDFN-EP)

Maxim MAX5969AETB+

U2 1

Current-mode PWM controller

(16 TQFN-EP)

Maxim MAX5974AETE+

U3 0 Not installed, phototransistor

(4 DIP)

U4 0 Not installed, shunt regulator

(5 SOT23)

— 1 PCB: MAX5969A EVALUATION

KIT

_________________________________________________________________ Maxim Integrated Products 3

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Component List (continued)

MagJack is a registered trademark of Bel Fuse Inc.

SUPPLIER PHONE WEBSITE

AVX Corporation 843-946-0238 www.avxcorp.com

Bel Fuse Inc. 201-432-0463 www.belfuse.com

Central Semiconductor Corp. 631-435-1110 www.centralsemi.com

Cooper Bussmann 916-941-1117 www.cooperet.com

Diodes Incorporated 805-446-4800 www.diodes.com

Fairchild Semiconductor 888-522-5372 www.fairchildsemi.com

International Rectifier 310-322-3331 www.irf.com

Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com

Panasonic Corp. 800-344-2112 www.panasonic.com

Pulse Engineering 858-674-8100 www.pulseeng.com

STMicroelectronics 408-452-8585 www.us.st.com

Sumida Corp. 847-545-6700 www.sumida.com

Taiyo Yuden 800-348-2496 www.t-yuden.com

TDK Corp. 847-803-6100 www.component.tdk.com

_________________________________________________________________ Maxim Integrated Products 4

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Component Suppliers

Note: Indicate that you are using the MAX5969A when contacting these component suppliers.

Quick Start

Required Equipment

• MAX5969AEVkit

• IEEE 802.3af/at-compliant PSE and Category 5e

Ethernet network cable

• -48V,1A-capableDCpowersupply

• Voltmeter

Hardware Connections

The 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) Use one of the following methods to power the EV kit:

• If network connectivity is required: Connect a

Category 5e Ethernet network cable from the EV

kit input port RJ45 connector to the correspond-

ing PSE Ethernet LAN connection, which provides

power to the EV kit. A modular Ethernet jack

(J1) provides an interface with the Ethernet data

signals only.

• If network connectivity is not required: Connect

a -48V DC power supply between the V+ and

V- PCB pads on the EV kit. Connect the power-

supply positive terminal to the V+ PCB pad and

the negative terminal to the V- PCB pad.

2) Activate the PSE power supply or turn on the external

DC power supply.

3) Using a voltmeter, verify that the EV kit provides +12V

across the VOUT and PGND PCB pads. PGND is

galvanically isolated from the EV kit’s input V+ and

WAD_IN PCB pads.

Detailed Description of Hardware

The MAX5969A EV kit features an Ethernet port network

PD interface-controller circuit for -57V supply rail systems.

The EV kit circuit contains a MAX5969A IEEE 802.3af/

at-compliant network PD interface controller and the

MAX5974A inductive-feedback, spread-spectrum, cur-

rent-mode PWM controller. The EV kit circuit is used in PoE

applications for powering PDs from an unshielded twisted-

pair (UTP) Category 5e Ethernet network cable and PSE

port using endspan or midspan Ethernet systems.

The EV kit demonstrates the full functionality of the

MAX5969A, such as PD detection, PD classification,

inrush current control, and UVLO. Resistors R1 and R4

set the PD detection signature and the PD classification

signatures, respectively.

The EV kit’s power circuit is a galvanically isolated 12W

power supply using the MAX5974A DC-DC current-

mode PWM controller in a synchronous-rectified flyback

DC-DC converter topology. The EV kit receives power

from an IEEE 802.3af/at-compliant PSE and a Category

5e Ethernet network cable connected to the EV kit’s

RJ45 MagJack. The EV kit uses a 1 x 1Gb Ethernet RJ45

MagJack and two full-bridge power rectifiers (D1, D2) to

separate the -57V DC power sent by the PSE. The EV kit

accepts power from an endspan or midspan PSE net-

work configuration. The EV kit also provides an Ethernet

jack (J1) for interfacing to the Ethernet data signals. PCB

pads V+ and V- are available for powering the EV kit

if network connectivity is not required. Common-mode

chokes L1 and L3 are provided for EMI filtering at the

EV kit power supply (V+, V-) and wall adapter (WAD_IN,

WAD_GND) inputs, respectively.

CLASS MAXIMUM POWER

USED BY PD (W)

RESISTOR

R4 (I)

00.44 to 12.95 619

10.44 to 3.84 118

23.84 to 6.49 66.5

36.49 to 12.95 43.2

412.95 to 25.5 30.9

5> 25.5 21.3

_________________________________________________________________ Maxim Integrated Products 5

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

The EV kit’s 12W, 300kHz flyback DC-DC converter uses

a MAX5974A inductive-feedback current-mode PWM

controller. The MAX5969A’s VDD and RTN pins provide

power for the DC-DC converter input circuit. The DC-DC

converter is configured for an output voltage of +12V

and provides up to 1A of output load current. The EV kit

circuit achieves up to 92% efficiency using MOSFET N2

for synchronous rectification on the secondary side. An

additional MOSFET N3 (SOT23) PCB pad is available

for increasing the output current load up to 2A with a

switching frequency of 400kHz. Transistor Q2 is provided

to limit the output overshoot at startup. Surface-mount

transformer T1 provides up to 1500V galvanic isolation

for the isolated output. Current-sense resistors R21 and

R25 limit the peak current through transistor N1 and

the primary of transformer T1. Primary-side feedback

regulation is achieved using T1 auxiliary winding and

voltage feedback resistors R3, R8, and R12 to set the

isolated output voltage. Diodes D6 and D7 are provided

for limiting the voltage spikes across transformer T1

during N1 turn-off time. The EV kit also includes additional

circuitry with uninstalled PCB pads to reconfigure the EV

kit using optocoupler feedback. See the Reconfiguring

the EV Kit for Optocoupler Feedback section for

additional information.

PD Classification Signature

The EV kit is configured for a Class 3 (6.49W to 12.95W)

PD classification by resistor R4. To reconfigure the PD

classification, replace surface-mount (0805) resistor R4.

Table 1 lists the PD classification options.

Wall Adapter Power Source

(WAD_IN, WAD_GND)

The EV kit can also accept power from a wall adapter

power source. Use the WAD_IN and WAD_GND (+30V

to +57V) PCB pads to connect the wall adapter power

source. The wall adapter power-source operating-volt-

age range must be within +36V to +57V for the EV kit.

When the wall adapter power source is above +36V, it

takes precedence over the PSE source. Once the wall

adapter power source is detected, The MAX5969A (U1)

internal isolation switch disconnects VSS from RTN. The

wall adapter power is supplied to VDD (through diode

D4 and RTN). Once it takes over, the PD internal switch

is turned off. Resistors R27 and R28 are available for

adjusting the EV kit wall adapter voltage for disabling the

PSE source.

If the wall adapter power source is below +27V, the PSE

provides power through the device’s RTN after a suc-

cessful detection and classification. Diode D4 prevents

the PSE from backdriving the wall adapter power source.

Ethernet Data-Signal Interfacing

The EV kit features Ethernet jack J1 to interface with

the Ethernet data signals. J1 is provided for interfacing

the EV kit with the Ethernet data signals only. Refer to

the RJ45 MagJack data sheet on the Bel Fuse website

prior to interfacing the EV kit’s J1 jack with the Ethernet

data signals.

Reconfiguring the EV Kit for

Optocoupler Feedback

The EV kit also supports an isolated DC-DC converter

design using optocoupler feedback. On the transformer’s

secondary side, PCB footprint pads are available for

shunt regulator U4, along with additional resistors and

capacitor components, providing secondary-side volt-

age feedback to the primary side through optocoupler

U3. The MAX5974A receives the voltage feedback signal

on the primary side from biasing resistors R51, R53, and

R54. When reconfiguring the EV kit for optocoupler feed-

back, the following modifications must be made:

• RemovecomponentsR3,R8,andR12(primary-side

feedback regulation components)

• InstalloptocouplerU3(4-pinDIPfootprint)

• InstallshuntregulatorU4(5-pinSOT23footprint)

• Install required surface-mount (0402/0603) resistor

and capacitor components for feedback regulation.

Table 1. PD Classification Selection

_________________________________________________________________ Maxim Integrated Products 6

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Figure 1a. MAX5969A EV Kit Schematic (Sheet 1 of 2)

_________________________________________________________________ Maxim Integrated Products 7

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Figure 1b. MAX5969A EV Kit Schematic (Sheet 2 of 2)

1.0” 1.0”

_________________________________________________________________ Maxim Integrated Products 8

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Figure 2. MAX5969A EV Kit Component Placement Guide—

Component Side

Figure 3. MAX5969A EV Kit PCB Layout—Component Side

Figure 4. MAX5969A EV Kit PCB Layout—Ground Layer 2

Figure 5. MAX5969A EV Kit PCB Layout—VCC Layer 3

1.0” 1.0”

_________________________________________________________________ Maxim Integrated Products 9

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Figure 6. MAX5969A EV Kit PCB Layout—Solder Side Figure 7. MAX5969A EV Kit Component Placement Guide—

Solder Side

PART TYPE

MAX5969AEVKIT# EV Kit

________________________________________________________________ Maxim Integrated Products 10

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Ordering Information

#Denotes RoHS compliant.

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 10/11 Initial release —

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 11

MAX5969A Evaluation Kit

Evaluates: MAX5969A/MAX5974A

Revision History