General Description

The MAX1582 evaluation kit (EV kit) is a fully assembled
and tested circuit board that evaluates the MAX1582
white LED step-up converter. The circuit operates from
2.6V to 5.5V and delivers 0 to 20mA to light a series of
up to six white LEDs. The evaluation kit has two groups
of white LEDs--a main group with four LEDs, and a
subgroup with two LEDs. These two groups of LEDs
have independent shutdown/enable control through
jumpers provided on the board. A flexible dimming fea-
ture allows the LED brightness to be controlled with
either an analog voltage or a PWM signal.

Features

o Constant Current Regulation for Uniform

Illumination

o Up to 84% Efficiency
o Flexible Analog or PWM Dimming Control
o Low 15mV

P-P

Input Ripple

o 0.9W Output Power with Internal 30V MOSFET

Switch

o Output Overvoltage Protection Eliminates Zener

Diode

o Small, Low-Profile Components
o 2.6V to 5.5V Input Range
o 0.01µA Shutdown Current
o Thin QFN 4mm x 4mm IC Package
o Fully Assembled and Tested

Evaluates: MAX1582

MAX1582 Evaluation Kit

________________________________________________________________ Maxim Integrated Products

19-2877; Rev 0; 5/03

Component List

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.

Ordering Information

PART

TEMP RANGE

IC PACKAGE

MAX1582EVKIT

-30

°C to +85°C

12 Thin QFN

DESIGNATION QTY DESCRIPTION

2.2µF, 6.3V X5R capacitor (0603)
Taiyo Yuden JMK107BJ225KA,
or Panasonic ECJ1VB0J225M,
or equivalent

0.1µF, 50V X7R capacitor (0603)
TDK C1608X7R1H104KT
or equivalent

0.022µF X7R capacitor (0603)
Taiyo Yuden TMK107BJ223KA
or equivalent

30V, 200mA Schottky diode (SOD-
323)
Central CMDSH2-3

D2D7

White LEDs
Nichia NSCW215T

DESIGNATION QTY DESCRIPTION

JU1, JU2

3-pin headers

JU3

2-pin header

22µH inductor (1210)
250mA, 710m

, 2.5 mm x 2.2 mm x

2.0mm
Murata LQH32CN220K

7.5

±1% resistor (0603)

100k

±5% resistor (0603)

MAX1582ETC (12-pin thin QFN 4 x 4)

MAX1582EBE (UCSP 4 x 4)

None

Shunts

None

MAX1582 EV kit PC board

Component Suppliers

SUPPLIER

PHONE

WEBSITE

Central
Semiconductor

631-435-1110

www.centralsemi.com

Kamaya

260-489-1533

www.kamaya.com

Murata

814-237-1431

www.murata.com

Nichia

248-352-6575

www.nichia.com

Panasonic

714-373-7939

www.panasonic.com

Sumida

847-956-0666

www.sumida.com

Taiyo Yuden

408-573-4150

www.t-yuden.com

TDK

847-803-6100

www.component.tdk.com

TOKO

847-297-0070

www.toko.com

Note: When contacting these suppliers, please specify you are
using the MAX1582.

Evaluates: MAX1582

MAX1582 Evaluation Kit

_______________________________________________________________________________________

Quick Start

Follow the steps below to verify board operation. Do
not turn on the power supply until all connections
are completed:

1) Verify the shunts on JU1 and JU2 are across pins 2

and 3.

2) Verify that a shunt is across the pins of jumper JU3.

3) Preset the power supply to between 2.6V and 5.5V.

4) Turn off the power supply.

5) Connect the power-supply positive terminal to the

V+ pad on the EV kit.

6) Connect the power-supply ground terminal to the

GND pad on the EV kit.

7) Turn on the power supply and verify that the LEDs

are lit.

Detailed Description

Enable/Shutdown

The LEDs on the MAX1582 EV kit are divided into two
groups--a main group consisting of D2D5 and a sub-
group consisting of D6 and D7. Connect pins 2 and 3
of JU1 to enable the main LED group, or connect pins 1
and 2 to disable the main LED group. Connect pins 2

and 3 of JU2 to enable the subgroup, or connect pins 1
and 2 to disable the subgroup (Table 1). If both LED
groups are disabled, then the IC enters low-power shut-
down mode.

Controlling LED Intensity

LED intensity is controlled using the CTRL input. CTRL
is used either as an analog input or a digital PWM input.
When using CTRL as an analog input, connect a 0 to
1.62V voltage source to CTRL, where 0V corresponds
to the dimmest setting, and 1.62V is full brightness.
Exceeding 1.62V does not increase brightness. For dig-
ital dimming, connect a PWM signal (200Hz to 200kHz)
directly to CTRL. In this case, the duty cycle controls
the brightness of the LEDs, where 0% duty cycle corre-
sponds to zero current and 100% duty cycle corre-
sponds to full current. PWM signal V

should equal 0V

and V

should exceed 1.62V.

A pullup resistor and jumper (R2 and JU3) are provided
so the evaluation kit can be used without an external
connection to CTRL. With JU3 shorted and no other con-
nection to CTRL, the LEDs are set to full brightness. If
CTRL is being driven, the shunt across JU3 can be
removed. Remove the shunt across JU3 when measur-
ing quiescent current with the circuit in shutdown mode;
otherwise excessive current is measured.

JUMPER

POSITION

FUNCTION

LEDs AFFECTED

1, 2

Disable

JU1

2, 3

Enable

D2D5

(main group)

1, 2

Disable

JU2

2, 3

Enable

D6, D7

(subgroup)

Short

100k

pullup resistor connected from CTRL to V+.

JU3

Open

CTRL open--must be driven externally.

Short

Shorts D2 so only D3, D4, and D5 are used in the LED main group.

JU4

Open

All four LEDs (D2D5) are used.

Short

LED main group connected.

JU5

Open

LED main group disconnected; connect external LEDs from OUT1 to OUT2.

Short

LED subgroup connected.

JU6

Open

LED subgroup disconnected; connect external LEDs from OUT2 to CS.

Table 1. Jumper Functions

Evaluates: MAX1582

MAX1582 Evaluation Kit

_______________________________________________________________________________________

MAX1582ETC

OUT1

PGND

OUT2

GND

COMP

EN2

EN1

V+

CTRL

C3
0.022

µF

JU2

JU1

GND

EN2

V+

EN1

CTRL

R2
100k

JU3

2.2

µF

V+

7.5

JU6
SHORT

0.1

µF

L1
22

µH

JU5
SHORT

JU4
OPEN

OUT1

OUT2

OUT1

PGND

OUT2

GND

COMP

EN2

EN1

V+

CTRL

MAX1582EBE

Figure 1. MAX1582 EV Kit Schematic

Changing the Number of LEDs

The MAX1582 can be used to drive a total of up to six
LEDs, and the MAX1582 EV kit comes configured for
driving six LEDs. To evaluate the MAX1582 driving
fewer than six LEDs, short out the pads of the unused
LEDs. To prevent excessive leakage in shutdown, there
must be at least two white LEDs in the circuit. For accu-
rate dimming control, there must be at least two white
LEDs in each group. If dimming is not required, this can
be reduced to one LED per group. For convenience,
JU4 can be used to short D2, reducing the number of
main LEDs to three.

Connecting External LEDs

Although the MAX1582 EV kit comes with surface-
mount LEDs installed, it can also be used to drive exter-
nal LEDs. For the main group, cut the PC board trace
shorting JU5, and connect a series string of two to six
white LEDs from OUT1 to OUT2. Connect the anode to
OUT1 and the cathode to OUT2. For the subgroup, cut
the PC board trace shorting JU6 and connect a series
string of two to three white LEDs from OUT2 to CS.
Connect the anode to OUT2 and the cathode to CS.
Ensure the total number of subgroup LEDs does not
exceed three.

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.

4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

Printed USA

is a registered trademark of Maxim Integrated Products.

Evaluates: MAX1582

MAX1582 Evaluation Kit

Figure 2. MAX1582 EV Kit Component Placement Guide--
Component Side

Figure 4. MAX1582 EV Kit PC Board Layout--Solder Side

Figure 3. MAX1582 EV Kit PC Board Layout--Component Side

Part Number MAX1582EVKIT