MAX5069A [MAXIM]

MAX5069A Evaluation Kit; MAX5069A评估板


型号：	MAX5069A
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	MAX5069A Evaluation Kit MAX5069A评估板
文件：	总9页 (文件大小：722K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-3513; Rev 0; 11/04

MAX5069A Evaluation Kit

General Description

Features

The MAX5069A evaluation kit (EV kit) is a fully assembled

and tested circuit board that contains a high-efficiency,

120W isolated push-pull DC-DC converter. The circuit is

configured for a +12V output voltage and provides up to

10A of output current. The circuit can be powered from

either a +36V to +72V or -36V to -72V DC source, as used

in the telecom/datacom markets, industrial environments,

or in automotive 42V power systems.

♦ 120W High-Efficiency, Isolated, Push-Pull DC-DC

Converter

♦ ±36V to ±72V Input Range

♦ +12V Output at 10A

♦ V

Regulation Better than 0.1% Over Line and

OUT

Load

High efficiency up to 91% is achieved at 10A while using

two n-channel primary-side MOSFETs switching at up to

90% combined duty cycle. On the secondary-side,

reduced output-voltage ripple and high efficiency is

achieved through full-wave rectification from a center-

tapped planar transformer. Galvanic isolation up to 500V

is achieved by an optocoupler and the planar surface-

mount transformer. The optocoupler helps in providing

isolated secondary-side regulation.

♦ 91% Efficiency at 48V and 10A

♦ Programmable Input UVLO

♦ Cycle-by-Cycle Current-Limit Protection

♦ Programmable Integrating Fault Protection

♦ 500kHz Oscillator Frequency

♦ External Clock SYNC Input

♦ Fully Assembled and Tested

Operation at 500kHz allows the use of small magnetics

and output capacitors. A SYNC input is featured to ease

synchronization to an external clock. The EV kit provides

cycle-by-cycle current-limit protection. Additional steady-

state fault protection is provided by the integrating fault

protection that reduces average dissipated power during

continuous overload conditions. The MAX5069A also has

a programmable input undervoltage lockout (UVLO) for

protection during brownout conditions. The EV kit may be

used to evaluate other versions of the MAX5069.

Ordering Information

PART

TEMP RANGE

IC PACKAGE

MAX5069AEVKIT

*With 200LFM airflow.

0°C to +50°C*

16 TSSOP

Component List

Warning: The MAX5069A 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 power the sources connected to it

must be careful to follow safety procedures appropriate to

working with high-voltage electrical equipment.

DESIGNATION QTY

DESCRIPTION

0.1µF 10%, 16V X7ꢀ ceramic

capacitor (0603)

Murata GꢀM39X7ꢀ104K016AD

1µF 10%, 100V X7ꢀ ceramic

capacitors (1210)

AVX 1210C105KAT9A

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.

C2, C3, C4

47µF 10%, 16V X5ꢀ ceramic

capacitors (1210)

Murata GꢀM32Eꢀ61C476K

C5, C6, C7,

C18, C19, C20

0.1µF 10%, 50V X7ꢀ ceramic

capacitor (0603)

Murata GꢀM188ꢀ71H104K

10µF 20%, 35V, low-impedance

electrolytic capacitor (5mm x 6mm)

Sanyo 35CV10KX

12pF 5%, 50V C0G ceramic

capacitor (0603)

C10

Murata GꢀM1885C1H120J

________________________________________________________________ Maxim Integrated Products

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.

MAX5069A Evaluation Kit

Component List (continued)

DESIGNATION QTY

DESCRIPTION

DESIGNATION QTY

DESCRIPTION

0.22µF 10%, 10V X7ꢀ ceramic

capacitor (0603)

TDK C1608X7ꢀ1C224K

200mA, 75V ultra-high-speed diode

(SOT323)

Central Semiconductor CMSD2838

C11

C12

C13

C14

560pF 5%, 50V C0G ceramic

capacitor (0603)

Murata GꢀM1885C1H561J

100mA, 80V switching diodes

(SOD-323)

Diodes Inc. 1N4148WS

D4, D5

1µF 10%, 16V X5ꢀ ceramic

capacitor (0603)

TDK C1608X5ꢀ1C105K

4.7µH, 17A inductor

Cooper HC2LP-4ꢀ7 or

Coilcraft D05010P-472HCB

0.033µF 10%, 16V X7ꢀ ceramic

capacitor (0603)

1000µH, 0.045A inductor

Coilcraft DS1608C-105

Murata GꢀM188ꢀ71E333K

200V, 3.2A n-channel MOSFETs

(SO-8)

Vishay Si7450DP or

4700pF 10%, 250VAC X7ꢀ

ceramic capacitor (2220)

Murata GA355Dꢀ7GC472K

N1, N2

C15

C16

C17

International ꢀectifier IꢀF7492

ꢀ1

ꢀ2

20.0kΩ 1% resistor (0603)

1.05kΩ 1% resistor (0603)

200kΩ 1% resistor (0603)

24.3kΩ 1% resistor (0603)

499kΩ 1% resistor (0805)

20.0kΩ 1% resistor (0805)

10kΩ 5% resistor (0805)

10kΩ 1% resistor (0603)

1MΩ 5% resistor (0603)

27kΩ 5% resistor (1206)

3Ω 5% resistors (1206)

220Ω 5% resistor (0603)

Not installed, resistor (2010)

Not installed, ceramic capacitor

(0603)

ꢀ3

0.015µF 10%, 50V X7ꢀ ceramic

capacitor (0603)

Murata GꢀM188ꢀ71H153K

ꢀ4

ꢀ5

ꢀ6

Not installed, ceramic capacitors

(1210)

47µF 10%, 16V X5ꢀ ceramic

capacitors (1210)

Murata GꢀM32Eꢀ61C476K

recommended

ꢀ7

ꢀ8

C21, C22

ꢀ9

ꢀ10

ꢀ11, ꢀ12

ꢀ13

ꢀ14

0.047µF 10%, 25V X7ꢀ ceramic

capacitor (0603)

Murata GꢀM188ꢀ71E473K

C23

C24

0.060Ω 1% resistor (2010)

IꢀC LꢀC-Lꢀ2010-01-ꢀ060-F

ꢀ15

470pF 10%, 100V C0G ceramic

capacitor (0805)

ꢀ16

ꢀ17

ꢀ18

ꢀ19

ꢀ20

ꢀ21

Not installed, resistor (0603)

15kΩ 5% resistor (0603)

1kΩ 1% resistor (0603)

2.2kΩ 5% resistor (0603)

5.1kΩ 5% resistor (0603)

10Ω 5% resistor (1206)

Murata GꢀM2165C2A471K

60V, 30A Schottky diode (TO-

220AB)

International ꢀectifier 30CTQ060 or

Vishay MBꢀ30H60CT

200mA, 75V, ultra-high-speed diode

(SOT323)

Central Semiconductor CMSD2836

_______________________________________________________________________________________

MAX5069A Evaluation Kit

Component List (continued)

DESIGNATION QTY

DESCRIPTION

Uninsulated banana jacks

ꢀubber bumpers

DESIGNATION QTY

DESCRIPTION

VOUT, SGND

None

ꢀ22

TB1

Not installed, resistor (1206)

2 points terminal block (0.2in center)

None

Zinc-plated metal screws, 4-40 x 1/4

Nylon hex nut 4-40

180W planar transformer

Coilcraft B0860-C

None

MAX5069AAUE (16-pin TSSOP-EP)

None

Nylon screw 4-40 x 3/8

High CTꢀ optocoupler

(ultra-small flat-lead)

NEC PS2911-1-M

TO-220 thermally conductive

insulating pad

None

TO-220AB aluminum heatsink

(10.4°C/W)

None

0.6V 0.5% shunt regulator

(SOT23-5)

Maxim MAX8515AEZK-T

MAX5069 PC board

Component Suppliers

SUPPLIER

PHONE

FAX

WEBSITE

www.avxcorp.com

www.cel.com

AVX

843-946-0238

408-588-2247

631-435-1110

847-639-6400

561-752-5000

310-322-3331

361-992-7900

770-436-1300

619-661-6835

847-803-6100

—

843-626-3123

408-588-2213

631-435-1824

847-639-1469

561-742-1178

310-726-8721

361-992-3377

770-436-3030

619-661-1055

847-390-4405

—

CEL/NEC; California Eastern Laboratories

Central Semiconductor

Coilcraft

www.centralsemi.com

www.coilcraft.com

www.cooperet.com

www.irf.com

Cooper-Coiltronics

International ꢀectifier

IꢀC

www.irctt.com

Murata

www.murata.com

www.sanyodevice.com

www.component.tdk.com

www.vishay.com

Sanyo Electronic Device

TDK

Vishay

Note: Indicate that you are using the MAX5069A when contacting these component suppliers.

DC-DC Converter Output

Quick Start

1) Connect the electronic load (+) terminal to the

VOUT banana jack. Connect the electronic load (-)

terminal to the SGND banana jack.

Required Equipment

•

36V to 72V power supply capable of providing up

to 6A

2) Connect a voltmeter to the VOUT and SGND termi-

nals to measure the output voltage.

•

20A electronic load e.g., HP 6060B

Voltmeter

3) Connect the positive terminal of a 36V to 72V power

supply to the +VIN terminal (TB1-1). Connect the

power supply’s ground to the -VIN terminal (TB1-2).

330µF, 100V bulk storage capacitor to be connected

to the input terminals of the EV kit

4) Turn on the electronic load and set it for “current

mode” and up to 5A of current.

•

A fan to provide at least 200LFM airflow for extended

operation at 10A

5) Turn on the power supply above 36V and verify that

the voltmeter reads +12V normally.

The MAX5069A EV kit is fully assembled and tested.

Follow these steps to verify board operation. Do not

turn on the power supply until all connections are

completed.

6) Verify that the electronic load is drawing the appro-

priate current.

_______________________________________________________________________________________

MAX5069A Evaluation Kit

The MAX5069A controller’s internal oscillator clock

switches at 500kHz and the frequency is programmed

by resistor ꢀ3. The duty cycle of both MOSFETs is var-

ied to control energy transfer to the output. The

MAX5069A EV kit’s maximum duty cycle is 90% as con-

figured. ꢀesistor ꢀ4 sets the dead time for both switch-

es and has an impact on the maximum duty cycle.

Detailed Description

The MAX5069A EV kit is a 120W, isolated, push-pull

DC-DC converter that provides +12V at up to 10A out-

put. The circuit can be powered from a 36V to 72V DC

source. The user should supply an additional 330µF

bulk storage capacitor between the input terminals

(+VIN, -VIN). This capacitor should be rated for 100V

and be able to carry approximately 2A of ripple current.

Lower ripple-current-rated capacitors should be

acceptable for short-term operation

The MAX5069A brownout and input-supply startup

UVLO threshold voltage is set by resistors ꢀ5 and ꢀ6.

This prevents the power supply from starting up or

operating below the programmed input supply voltage.

Test point TP1 is provided to connect an external clock

to the SYNC pin on the MAX5069A.

The push-pull converter achieves high efficiency by

using two external n-channel MOSFETs on the primary

side that can switch up to 90% combined duty cycle

that results in lower primary ꢀMS currents through the

MOSFET switches resulting in improved efficiency.

The EV kit’s PC board layout is a 4-layer 2oz copper

PC board.

Cycle-by-cycle current limiting prevents the primary

current from reaching destructive levels, whereas the

fault integration feature provides hiccup fault protec-

Evaluating Other Output Voltages,

Current Limits, UVLOs

Output Voltage

OUT

tion. For a continuous short circuit at the output, the

MAX5069’s fault integration feature provides hiccup

fault protection. This greatly minimizes destructive tem-

perature rise during persistent overload conditions. Pin

8 of the MAX5069A, capacitor C11, and resistor ꢀ9

form the fault integration circuit. Current-sense resistors

ꢀ14 and ꢀ15 sense the current through the primary of

transformer T1 and turn off the respective MOSFET (N1

or N2) that is switching when the trip level of 314mV

(typ) is reached.

The MAX5069A EV kit’s output (V

) is set to +12V by

OUT

feedback resistors ꢀ1 and ꢀ2. To generate other output

voltages in the vicinity of +12V (from +8V to +15V, limit-

ed by the output capacitor and diode D1 voltage rat-

ing), select different voltage-divider resistors (ꢀ1, ꢀ2).

ꢀesistor ꢀ2 is typically chosen to be less than 2kΩ.

Using the desired output voltage, resistor ꢀ1 is then

found by the following equation:









OUT

ꢀ1 = ꢀ2

−1







The planar surface-mount transformer features a bias

winding that, along with diode-pair D2, D3, and inductor

L2, provide full-wave rectification for the bias voltage

powering the MAX5069A once the input voltage is stable.

Upon initial input-voltage application, bootstrap resistor

ꢀ10 and reservoir capacitor C9 enable the MAX5069A to

startup within approximately 200ms. The transformer uses

a secondary-side center tap and dual Schottky diode D1

to provide full-wave rectification for reduced output-volt-

age ripple. When either MOSFET is turned off and the

alternate turned on, both D1 diodes are conducting. The

transformer provides galvanic isolation up to 500V.

ꢀesistor ꢀ21 and capacitor C24 form a snubber network

that suppresses transient overvoltage ringing at diode D1

caused by transformer T1 leakage inductance and diode

D1 junction capacitance.









ꢀEF

where V

= 0.6V

ꢀEF

The maximum output current should be limited to less

than 10A. The usable output voltage range for the EV kit

is +8V to +15V. Additionally, ICs U3, U2, and resistor ꢀ19

limit the minimum output voltage (V

voltages outside the above range, a different turns ratio

transformer may be required.

) to +2.6V. For

OUT

Current Limiting

The EV kit features cycle-by-cycle current limiting of the

transformer primary current. Current-sense resistors

ꢀ14 and ꢀ15 sense the current through the primary of

transformer T1 and turn off MOSFET N1 or N2 when the

trip level of 314mV (typ) is reached. Current-sense

resistors ꢀ14 and ꢀ15 limit the peak primary current to

approximately 5.3A (314mV / 0.060Ω ≈ 5.3A). This will

limit short-circuit current on the secondary output

(VOUT) to 20A typically. To evaluate lower current lim-

its, current-sense resistors ꢀ14 and ꢀ15 must be

replaced with different value surface-mount resistors

(2010 size) as determined by the following equation:

On the transformer’s secondary side, a 0.6V shunt reg-

ulator (MAX8515, U3) along with feedback resistors ꢀ1

and ꢀ2 provide secondary-side voltage feedback

through optocoupler U2 to the primary side. The

MAX5069A receives the voltage feedback signal on the

primary side from biasing resistors ꢀ16, ꢀ17, ꢀ18, and

optocoupler U2.

_______________________________________________________________________________________

MAX5069A Evaluation Kit

Push-Pull DC-DC Converter

SENSE

ꢀ





× 1.2 × I

(

)

OUTMAX









where ꢀ

SENSE

= parallel combination of ꢀ14 and ꢀ15,

N1 DRAIN VOLTAGE

= 0.314V, N = 2, N = 5, and I

= max-

OUTMAX

imum DC output current (10A or less). Note that some

fine-tuning may be required when selecting the current-

limit resistors. Errors are introduced as a result of the

MAX5069A IC current-limit propagation delays.

N2 DRAIN VOLTAGE

Input Undervoltage Lockout (UVLO)

The MAX5069A EV kit features a brownout and input-

supply startup UVLO circuit that prevents operation

below the programmed input-supply start voltage.

ꢀesistors ꢀ5 and ꢀ6 set the input undervoltage lockout

threshold of the EV kit. To evaluate other input UVLO

voltages, replace resistor ꢀ5 with another surface-mount

resistor (0805 size). Using the desired startup voltage,

resistor ꢀ5 is then found by the following equation:

1µs/div

Figure 1. MOSFETs N1 and N2 Drain-Source Voltage Waveforms

(50V per Division, 1µs per Division)

VIN





STAꢀTUP

ꢀ5 =

−1 × ꢀ6







1.231V



where VIN

is the desired startup voltage at which

STAꢀTUP

the EV kit starts and resistor ꢀ6 is typically in the 20kΩ

range. ꢀefer to the MAX5069A/D UVLO Adjustment and

Bootstrap Undervoltage Lockout sections of the

MAX5069 data sheet for additional information on the

UVLO/EN pin of the MAX5069A IC.

_______________________________________________________________________________________

MAX5069A Evaluation Kit

Figure 2. MAX5069A EV Kit Schematic

_______________________________________________________________________________________

MAX5069A Evaluation Kit

Figure 3. MAX5069A EV Kit Component Placement Guide—Component Side

Figure 4. MAX5069A EV Kit PC Board Layout—Component Side

_______________________________________________________________________________________

MAX5069A Evaluation Kit

Figure 5. MAX5069A EV Kit PC Board Layout—Inner Layer, GND Plane

Figure 6. MAX5069A EV Kit PC Board Layout—Inner Layer, VCC Plane

_______________________________________________________________________________________

MAX5069A Evaluation Kit

Figure 7. MAX5069A EV Kit PC Board Layout—Solder Side

Figure 8. MAX5069A EV Kit Component Placement Guide—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 _____________________ 9

Printed USA

is a registered trademark of Maxim Integrated Products.

MAX5069A [MAXIM]

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