Maxim Integrated MAX17509 Quick Start Manual

MAX17509 Evaluation Kit

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

General Description

The MAX17509 evaluation kit (EV kit) is a fully assembled
and tested circuit board to demonstrate the performance

of the MAX17509, a dual 3A, high-efciency, synchronous

step-down DC-DC converter. The EV kit operates from a

4.5V to 16V input voltage to generate two, independent

3.3V and 1.2V outputs, with each regulator delivering
up to 3A continuous output current. The EV kit is preset
to the default 1MHz switching frequency for optimum
efciency and component sizes, and each regulator
operates 180° out-of-phase to reduce input-voltage ripple
and total RMS input ripple current. The EV kit also
features adjustable input undervoltage-lockout (UVLO),
programmable frequency, external frequency synchro­nization input, adjustable output voltage ranging from

0.904V to 3.782V and 4.756V to 5.048V with 20mV
resolution, selectable switching slew rate, adjustable soft­start time with soft-stop option, power-good outputs, and
selectable overcurrent (OC) fault response to promote

design exibility and system reliability.

Features

● Wide Input-Voltage Range (4.5V to 16V)

● 3.3V and 1.2V Output Voltages

● Up to 3A Output Current per Regulator

● Two Independent Outputs Operating 180° Out-of-

Phase

● 1MHz Switching Frequency

● External Frequency Synchronization Input

● Brickwall and Latchoff Overcurrent Response

(Selectable to Hiccup Response)

● Autoconfigured Internal Compensation

● Power-Good Output Indicator

● Independent Adjustable EN/UVLO Input

● Independent Adjustable Soft-Start Time with Soft-

Stop Option

● Selectable Switching Slew Rate for EMC Compliant

● Low-Profile and Small-Size, Surface-Mount

Components

● Fully Assembled and Tested

Quick Start

Recommended Equipment

● MAX17509 EV kit

● 4.5V to 16V, 4A DC input power supply

● Two loads capable of sinking 3A

● Digital voltmeters (DVM)

● 100MHz dual-trace oscilloscope

Procedure

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) Set the power supply at a voltage between 4.5V and
16V. Disable the power supply.

2) Connect the positive and negative terminals of the
power supply to IN and PGND PCB pads, respectively.

3) Connect the positive and negative terminals of the
rst 3A load to OUT1 and PGND PCB pads, respec­tively, and the second 3A load to OUT2 and PGND
PCB pads, respectively. Set both loads to 0A.

4) Connect the rst DVM across the OUT1 and PGND
PCB pads, and the second across OUT2 and PGND,
respectively.

5) Change the position of SW1 and SW2 to position 1-2
(or 2-3) to enable the respective regulator. SW1 and
SW2 in the middle position will disable the device.

6) Enable the input power supply.

7) Verify that DVM1 displays 3.3V and DVM2 displays

1.2V.

8) Increase the load up to 3A to verify that DVM
continues displaying 3.3V and 1.2V, respectively.
Note that the EV kit is designed to demonstrate com­pact solution-size so that the output voltage-sensing
is performed near C2 for VOUT1 and C3 for VOUT2.
Therefore, the output voltage is accurate across
those respective components.

Ordering Information appears at end of data sheet.

19-7670; Rev 0; 6/15

MAX17509 Evaluation Kit

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

Detailed Description of Hardware

The EV kit is a proven circuit to demonstrate the high-

efciency and compact solution-size of the synchronous

step-down DC-DC regulators. The EV kit operates from
a 4.5V to 16V input voltage to generate two independent

3.3V and 1.2V outputs, with each regulator delivering up
to 3A continuous output current. The switching frequency

is set to 1MHz to balance efciency and component

size. The EV kit includes switches SW1,2 to enable/

disable the device, test point TP1 to optionally synchro­nize to an external clock source (SYNC), and LED1,2
connected to PGOOD1,2 to indicate the status of the
outputs. Additional footprints of optional components are

included to ease board modication for different input/
output congurations. Table 1 displays the resistor

programming options. When the output voltage is changed,
refer to the MAX17509 IC data sheet’s recommendation on
the inductance and capacitance selection criteria.

Table 1. Summary of Resistor Programming

Index 1% RES.

(kΩ) MODE

475 (OPEN

0

1 200 1.0MHz 4 4 0.019

2 115 1.5MHz 8 8 0.037

3 75 2.0MHz 16 16 0.966 0.057

4 53.6

5 40.2 1.0MHz 4 4 1.597 0.097

6 30.9 1.5MHz 8 8 1.912 0.115

7 24.3 2.0MHz 16 16 2.228 0.135

8 19.1

9 15 1.0MHz 4 4 2.859 0.176

10 11.8 1.5MHz 8 8 3.174 0.194

11 9.09 2.0MHz 16 16 3.490 0.213

12 6.81 500kHz

13 4.75 1.0MHz 4 4

14 3.01 1.5MHz 8 8

15 GND 2.0MHz 16 16

or VCC)

TWO SINGLE-PHASE

R13

MODE

PHASE

SHIFT

180°

0°

INDEPENDENT OUTPUTS

180°

DUAL-PHASE, SINGLE OUTPUT

F

SW

500kHz

500kHz

500kHz

OC SSTOP1

BRICKWALL AND LATCHOFF

HICCUP

R1

SS1

DISABLE

ENABLE

DISABLE

ENABLE

TSS1

(ms)

1

1

1

1

LX-

SLEW

MAXIMUM

MINIMUM

R2

SS2

SSTOP2

DISABLE

ENABLE

DISABLE

ENABLE

R5, R8

COARSE_

TSS2

(ms)

COARSE

V

(V)

OUT

1

0.650

1 1.281 0.078

1 2.543 0.157

1

4.756

(7V VIN)

4.756

(9V VIN)

4.756

(12V VIN)

4.756

(16V VIN)

R6, R7

FINE_

FINE

V

OUT

0.000

0.235

0.254

0.272

0.291

(V)

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│

2

MAX17509 Evaluation Kit

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

Regulator Enable and Adjustable UVLO

The device can be self-enabled by connecting EN_ to
AVCC, and can optionally be programmed to turn on at
the input-voltage threshold by connecting EN_ to the
resistor-divider between IN_ to GND. The EV kit has
SW1 and SW2 to enable regulator 1 and 2, respectively,
through the input supply or AVCC. Moving the switches
to position 1 enables the device at a 4.1V input UVLO
threshold, while moving to position 3 connects EN_ to
AVCC. Moving a switch to position 2 will disable the
respective regulator. The adjustable-input UVLO threshold
of a regulator can be programmed with top feedback
resistor RU connected between IN_ and EN_, and bottom
feedback resistor RB connected between EN_ and GND.
The adjustable-input UVLO threshold of regulator 1 can
be programmed with the resistor-dividers R15 (RU1) and
R3 (RB1), and regulator 2 with R16 (RU2) and R10 (RB2).

Choose RU_ and then calculate RB_ with the following
equation:

RB_= RU_x

Where VINU is the input threshold voltage at which the
device is required to turn on. Ensure that VINU is higher
than 0.93 x V

OUT

.

V

INU

1.262

- 1.262

Mode/Phase Shift/ Switching Frequency
(MODE)

The MODE pin sets the device as a single-phase, dual­output/dual-phase, or single-output, while also setting the
phase-shift and switching frequency. The EV kit operates

in a single-phase, dual-output conguration, each with

up to 3A output current. Each regulator operates with
180° out-of-phase and 1MHz switching frequency. The
phase-shift mode can be selected to be either 0° or 180°
out-of-phase in the dual-output mode only. The device is

also capable of conguring different switching frequency

options: 0.5MHz, 1MHz, 1.5MHz, and 2MHz for input voltage
up to 6V.

Soft-Start/Soft-Stop Options and Over-Current
Response (SS1)

The SS1 pin sets regulator 1’s soft-start timing among 1,
4, 8, and 16ms, as well as its soft-stop option. The SS1 pin
also sets options to attempt regulation following an under
and overcurrent event. The two options for fault response
due to UC/OC protection are: (1) hiccup and (2) Brickwall
and latchoff. The EV kit is set to 8ms soft-start timing,
with soft-stop enabled for regulator 1, and Brickwall-and­latchoff overcurrent response for both regulators.

Soft-Start/Soft-Stop Options and Switching
Slew rate (SS2)

The SS2 pin sets regulator 2’s soft-start timing among 1,
4, 8, and 16ms, as well as its soft-stop option. The SS2
pin also sets the switching slew rate of both regulators
to either maximum or minimum. The EV kit is set to 8ms
soft-start timing, with soft-stop enabled, for regulator 2,
and maximum switching slew rate for both regulators.

External Clock Synchronization (SYNC)

The SYNC pin allows frequency-synchronization to
external clock. The EV kit provides a SYNC test point (TP1)
that allows connecting an external clock for frequency
synchronization with frequency within the 900kHz
to 1.3MHz range before regulation starts for stable
operation of 1MHz internal switching frequency at the

range, and within 0.7–2.75 of the internal switching

12V

IN

frequency, with a limit of 450kHz to 2.2MHz for the 5V
range. The minimum external clock high pulse width
should be greater than 30ns. The minimum voltage
should be below 0.6V, with the maximum level being
above 1.8V (e.g., 0 to 5V).

IN

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│

3

MAX17509 Evaluation Kit












Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

Programmable Output Voltage

The device generates an independently adjustable output
voltage in the ranges of 0.904V to 3.782V and 4.756V to

5.048V in 20mV steps. The EV kit provides 3.3V on regu­lator 1 and 1.2V on regulator 2. The target output voltage
(V

) is determined by the sum of COARSE voltage

OUT

(COARSE_) and FINE voltage (FINE_), which can be
programmed by connecting resistors from COARSE

Where V
value of V

OUTCOARSE

OUT

the FINE resistor value from Table 1. Table 2 summarizes
the resistor setting and the optimal inductor and output
capacitor selection for typical output voltages for typical
12VIN range. Consult the MAX17509 IC data sheet’s
recommendation on the inductance and capacitance
value, as well as the guideline for the 5VIN range.

is the COARSE_ closest to the

; Index is the index number selected for

and FINE pins to GND. The COARSE-resistor value is
selected according to the closest COARSE_ voltage less
than or equal to the target output voltage from Table 1.
The FINE resistor value is chosen by the index number,
calculated by the following equation:

Index

0.02

VV

−

OUT OUTCOARSE

=

Table 2. Summary of Resistor Setting and the Optimal Inductor and Output Capacitor
Selection for Typical Output Voltages

V

(V) COARSE INDEX

OUT

0.9 2 13 115 4.75 1 100

1.0 3 2 75 115 1.2 82

1.2 3 12 75 6.81 1.2 68

1.5 4 11 53.6 9.09 1.5 55

2.0 6 5 30.9 40.2 2.2 41

2.5 7 14 24.3 3.01 2.2 33

3.0 9 7 15.0 24.3 2.2 18

3.3 10 7 11.8 24.3 2.2 18

5.0 (7V VIN)

5.0 (9V VIN)

5.0 (12V VIN)

5.0 (16V VIN)

12
13
14
15

FINE

INDEX

13

COARSE

RESISTOR (kΩ)

6.81

4.75 2.7

3.01 3.9

GND 4.7

FINE

RESISTOR (kΩ)

4.75

6 ≤ VIN ≤ 16V, FSW = 1MHz

L

(μH) C

MIN

1.8

OUTMIN

18

(μF)

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4

MAX17509 Evaluation Kit

3.250

3.255

3.260

3.265

3.270

3.275

3.280

0.0 0.5 1.0 1.5 2.0 2.5 3.0

V

OUT

(V)

OUTPUT CURRENT (A)

LOAD REGULATION

V

OUT

= 3.3V

toc03

VIN= 16V

VIN= 5V

VIN= 12V

EV Kit Performance Report

V

= 3.3V

EFFICIENCY vs. OUTPUT CURRENT

100

95

90

85

80

75

EFFICIENCY (%)

70

65

60

0 1000 2000 3000

OUT1

VIN= 12V

VIN= 16V

OUTPUT CURRENT (mA)

VIN= 5V

EN2 = 0V

toc01

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

V

= 1.2V

EFFICIENCY vs. OUTPUT CURRENT

90

85

80

75

EFFICIENCY (%)

70

65

60

0 1000 2000 3000

1.210

OUT2

VIN= 12V

VIN= 16V

OUTPUT CURRENT (mA)

LOAD REGULATION

= 1.2V

V

OUT

toc02

VIN= 5V

EN1 = 0V

toc04

1.205

VIN= 16V

1.200

(V)

V

OUT

1.195

1.190

1.185

VIN= 5V

VIN= 12V

0.0 0.5 1.0 1.5 2.0 2.5 3.0

OUTPUT CURRENT (A)

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5

MAX17509 Evaluation Kit

LOAD SHORT-CIRCUIT SHUTDOWN (LATCH)

VIN= 12V, V

OUT

= 1.2V

500mV/div

toc09

4µs/div

LX

V

OUT

10V/div

PGOOD

5V/div

I

L

2A/div

EV Kit Performance Report (continued)

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

LOAD CURRENT TRANSIENT RESPONSE

V

= 12V, V

IN

V

OUT

I

OUT

OUT

= 3.3V, I

40us/div

STARTUP/SOFT-STOP ENABLED

V

PGOOD

V

EN

OUT

= 12V, V

IN

OUT

= 1.2V, I

= 1.5 - 3A

OUT

= 0A, TSS= 8ms

OUT

toc05

200mV/div
(AC
COUPLED)

1A/div

toc07

5V/div

2V/div

500mV/div

LOAD CURRENT TRANSIENT RESPONSE

V

= 12V, V

IN

V

OUT

I

OUT

OUT

= 1.2V, I

40µs/div

STARTUP/SOFT-STOP ENABLED

V

PGOOD

V

EN

OUT

IN

= 12V, V

OUT

= 1.2V, I

= 1.5–3A

OUT

= 3A, TSS= 8ms

OUT

toc06

50mV/div
(AC
COUPLED)

1A/div

toc08

5V/div

5V/div

500mV/div

LX

4ms/div

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10V/div

LX

SYNCHRONIZATION vs. LX1 and LX2

180° OUT-OF-PHASE

CLKIN

LX1

LX2

400ns/div

4ms/div

10V/div

toc10

5V/div

10V/div

10V/div

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│

6

MAX17509 Evaluation Kit

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

Figure 1. MAX17509 EV Kit Component Placement Guide—
Component Side

Figure 3. MAX17509 EV Kit PCB Layout—Component Side

Figure 2. MAX17509 EV Kit Component Placement Guide—
Solder Side

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Figure 4. MAX17509 EV Kit PCB Layout—PGND Layer 2

Maxim Integrated

│

7

MAX17509 Evaluation Kit

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

Figure 5. MAX17509 EV Kit PCB Layout—PGND Layer 3 Figure 6. MAX17509 EV Kit PCB Layout—Solder Side

Component Information and Schematic

See the following links for component information and
schematic:

● MAX17509 EV BOM

● MAX17509 EV Schematic

Ordering Information

PART TYPE

MAX17509EVKIT# EV Kit

#Denotes RoHS compliant.

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8

MAX17509 Evaluation Kit

Evaluates: MAX17509 4.5V–16V,

Dual 3A Synchronous Buck Converter

Revision History

REVISION

NUMBER

0 6/15 Initial release —

REVISION

DATE

DESCRIPTION

PAGES

CHANGED

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.

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 specications without notice at any time.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.

©

2015 Maxim Integrated Products, Inc.

│

9

PGND

PGND

PGND

SHEET 2 OF 2

2/3/2015

MAX17509 EVKIT

EPCB17509

A

1.2

22UF

OPEN

1%

11.8K

10UF 10UF0.1UF

2.2UF

OPEN

OPEN

1%

42.2K

49.9

30.9K

1% 1%

200K

1%

10K

1% 1%

42.2K

1%

10K

1%

1%

100UF

1K

1%

MAX17509

1%

75K

1%

19.1K

OPEN

0.1UF

1K

G13AP

OPEN

19.1K

OPEN

0.1UF

OPEN

30.9K 6.81K

1%

1UF

OPEN

49.9

1.5UH

0.1UF

2.2UH

1%

1%1%

24.3K

G13AP

C2

R5

C5

IN

LED1

R19

C10

R1

OUT2

R10

R15 R16

R13

R14

LED2

R11

R8

R9R4

C4

U1

C1

R3

C7

C9

TP1

C15 C16

C3

C6

SW2

R12

R17

C12

R2C8R7

OUT1

C13

C14

L2

C17

R18

L1

R6

SW1

OUT1

AVCC VCC SYNC

IN AVCC IN

OUT2

VCC

IN

IN

VCC

IN

AVCC

2 1

2 1

11 15141310

4

6

5

4

K A

29

169

23

3

2

214

196

30

33

2532 26

178

6

18

12

7

A

5

K

31

1 24

27

22

20

28

5

6

5

4

6

5

4

EN1

COARSE1

FINE1

SS1

SS2

FINE2

COARSE2

EN2

OUT2

PGND2

PGND2

LX2

LX2

IN2

IN2

BST2

EP

PGOOD2

MODE

N.C.

SYNC

VCC

AVCC

SGND

PGOOD1

BST1

IN1

IN1

LX1

LX1

PGND1

PGND1

OUT1

DRAWN BY:

TEMPLATE REV:

REV:

2

B

D

1

C

A

2345

345

678

C

B

A

8 7 6 1

D

DATE:

PROJECT TITLE:

DRAWING TITLE:

SIZE

HARDWARE NUMBER:

ENGINEER:

B

B

BILL OF MATERIALS (BOM) 6/16/15 Revision

Remarks QTY Component Manufacturer

(Reference Designators)

Per Description Part Number

C2

1

CAP CER 22UF 10V 10% X7R 1206

Murata GRM31CR71A226KE15 (10V, X7R, 10%)

C13

1 1uF ±10%, 16V X7R ceramic capacito r (0603)

Murata GRM188R71C105K

C14

1

2.2uF ±10%, 10V X5R ceramic capaci tor (0603) Murata GRM188R71A225K

C9, C10

2 CAP CER 0.1UF 25V 10% X7R 0603

Murata GRM188R71E104KA01D

C7, C12

2

0.1uF 10%, 16V X7R ceramic capacito rs (0603) TDK C1608X7R1C104K

C5, C8

2 10uF ±10%, 25V X7R ceramic capacito rs (1206)

Murata GRM31CR71E106K

C4

1 CAP CER 100UF 6.3V 20% X5R 1206 TDK C3216X5R0J107M160AB

C3, C15, C16, C17

0 Not Installed, ceramic capacitors (1206)

C1, C6 0

Not Installed, ceramic capacitors (0603)

L2

1 1.5uH ±20%, 21.45mohm inductor (4mm x 4mm x 2.1mm)

Coilcraft XAL4020-152ME_

Wurth WE-LHMI 74437324015 (1.5uH ±20%, 34.8mOhm inductor)

L1

1

2.2uH ±20%, 35.2mohm inductor (4mm x 4mm x 2.1mm)

Coilcraft XAL4020-222ME_

Wurth WE-LHMI 74437324022 (2.2uH ±20%, 51mOhm i nductor)

LED1, LED2

2

LED, YELLOW (0603) LITE-ON LTST-C190YKT

IN, PGND1-PGND3, OUT1, OUT2

6

9020 BUSS EVK KIT PARTS; MAXIM PAD; WIRE; NATURAL;

SOLID; WEICO WIRE; SOFT DRAWN BUS TYPE-S; 20AWG

9020 BUSS

U1

1

Maxim MAX17509ATJ+ Maxim MAX17509ATJ+

R1, R2

2

30.9k ohm ±1%, resistor (0402)

R3, R10

2

19.1k ohm ±1%, resistor (0402)

R4, R9

2

10k ohm ±1%, resistor (0402)

R5

1

11.8k ohm ±1%, resistor (0402)

R6

1

24.3k ohm ±1%, resistor (0402)

R7

1

6.81k ohm ±1%, resistor (0402)

R8

1

75k ohm ±1%, resistor (0402)

R11, R14

2

1k ohm ±1%, resistor (0402)

R13

1

200k ohm ±1%, resistor (0402)

R15, R16

2

42.2k ohm ±1%, resistor (0402)

R17, R18

2

49.9 ohm ±1%, resistor (0402)

SW1, SW2

2

SWITCH TOGGLE SPDT 0.4VA 20V NKK G13AP

R12 0 Not Installed, resisto r (0402)

R19 0 Not Installed, resisto r (0603)

TP1

1

TEST POINT “Miniature" (RED)

Keystone 5000