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General Description

The MAX16818 evaluation kit (EV kit) is a fully assem-

bled and tested surface-mount printed-circuit board

(PCB) designed to evaluate the MAX16818 pulse-width

modulation (PWM) LED driver controller in a buck-boost

configuration.

The MAX16818 EV kit operates from a DC supply volt-

age of 6V to 28V. The EV kit’s output is configured to

deliver at least 1A of current into an 18V series LED

string. The LED brightness can be dimmed using a dig-

ital PWM signal.

The EV kit provides an option to configure the

MAX16818 IC’s overvoltage protection, switching fre-

quency, and frequency compensation. The MAX16818

EV kit also features a 180° out-of-phase clock output

PCB pad.

Features

♦ 6V to 28V Input-Voltage Range

♦ 1A Output Current into an 18V LED String

♦ Pulse-Width Modulated LED Current Dimming

♦ Resistor-Adjustable Overvoltage Protection and

Switching Frequency

♦ 180° Out-of-Phase Clock Output

♦ Fully Assembled and Tested

Evaluates: MAX16818

MAX16818 Evaluation Kit

________________________________________________________________

Maxim Integrated Products

19-0842; Rev 0; 6/07

Component List

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.

Ordering Information

PART TEMP RANGE IC PACKAGE

MAX16818EVKIT+ 0°C to +70°C* 28 TQFN-EP**

DESIGNATION QTY DESCRIPTION

C1 1

2.2µF ±10%, 50V X7R ceramic

capacitor (1206)

Murata GRM31CR71H225K

C2 1

1µF ±20%, 50V X7R ceramic

capacitor (0805)

Murata GRM21BR71H105M

C3 1

4.7µF ±10%, 6.3V X7R ceramic

capacitor (0603)

Murata GRM188R70J475K

C4 1

0.47µF ±10%, 6.3V X7R ceramic

capacitor (0603)

Murata GRM188R70J474K

C5 1

1000pF ±10%, 50V X7R ceramic

capacitor (0603)

Murata GRM188R71H102K

C6, C7 2

10µF ±10%, 50V X7R ceramic

capacitors (2220)

Murata GRM55DR71H106K

C8, C10 0 Not installed, capacitors (0603)

C9 1

0.22µF ±10%, 16V X7R ceramic

capacitor (0603)

Murata GRM188R71C224K

C11 1

2200pF ±10%, 50V X7R ceramic

capacitor (0603)

Murata GRM188R71H222K

DESIGNATION QTY DESCRIPTION

C12 1

0.1µF ±10%, 16V X7R ceramic

capacitor (0603)

Murata GRM188R71C104K

C13 1

100pF ±5%, 50V C0G ceramic

capacitor (0603)

Murata GRM1885C1H101J

C14 1

100µF, 50V electrolytic capacitor

(8mm x 10.2mm)

Panasonic EEEFK1H101P

D1 1

60V, 2A Schottky diode (SMB)

Diodes Inc. B260-13-F

JU1 1 3-pin header

JU2 1 2-pin header

L1 1

8.8µH, 4A

inductor

Sumida CDEP105-8R8

N1 1

40V , 4.9A n- channel M OS FE T ( S O8)

V i shay S i 4446D Y

N2–N5 4

60V, 115mA n-channel MOSFETs

(SOT23)

Central Semiconductor 2N7002

LEAD-FREE

P1 1

-20V, -3.8A p-channel MOSFET

(TSOP-6)

Vishay Si3467DV-T1-E3

Denotes a lead-free and RoHS-compliant EV kit.

This limited temperature range applies to the EV kit PCB only.

The MAX16818 IC temperature range is -40°C to +125°C.

EP = Exposed paddle.

Summary of content (6 pages)

PAGE 1
9-0842; Rev 0; 6/07 MAX16818 Evaluation Kit The MAX16818 evaluation kit (EV kit) is a fully assembled and tested surface-mount printed-circuit board (PCB) designed to evaluate the MAX16818 pulse-width modulation (PWM) LED driver controller in a buck-boost configuration. The MAX16818 EV kit operates from a DC supply voltage of 6V to 28V. The EV kit’s output is configured to deliver at least 1A of current into an 18V series LED string. The LED brightness can be dimmed using a digital PWM signal.
PAGE 2
MAX16818 Evaluation Kit Evaluates: MAX16818 Component List (continued) DESIGNATION QTY DESCRIPTION Q1 1 Q2 1 R1 R2 R3, R7, R15, R16 R4, R5 R6 R8 R9 R10 R11 R12, R13 1 1 NPN bipolar transistor (SOT223) Fairchild Semiconductor PZT3904 PNP bipolar transistor (SOT23) Fairchild Semiconductor MMBT3906 1kΩ ±1% resistor (1206) 12.1kΩ ±1% resistor (0603) 4 10kΩ ±1% resistors (0603) 2 1 1 1 1 1 2 R14 1 R17 1 1Ω ±1% resistors (0603) 4.
PAGE 3
MAX16818 Evaluation Kit Recommended Equipment Before beginning, the following equipment is needed: • 6V to 28V, 5A DC power supply • A series-connected LED string rated at 1A (maximum voltage on the string should not exceed 18V) • A current probe to measure LED current • One voltmeter Procedure The MAX16818 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.
PAGE 4
Evaluates: MAX16818 MAX16818 Evaluation Kit Clock Output Output Enable (EN) The MAX16818 EV kit also features a digital clock output that is 180° out-of-phase with respect to the highside driver, N1. The clock output is available at the CLKOUT PCB pad. Jumper JU2 controls the output enable pin on the MAX16818 IC. The MAX16818 output enable pin (EN) is also connected to the overvoltage protection circuitry on the EV kit (see Table 2 for shunt positions).
PAGE 5
_______________________________________________________________________________________ PGND R8 221kΩ 1% Q2 C14 100μF 50V 3 2 1 R6 4.99kΩ 1% 5 2 2 R10 12.4kΩ 1% R9 100kΩ 1% VCC U3 1 C1 2.2μF 50V VIN 5 1 U4 R7 10kΩ 1% R3 10kΩ 1% 3 2 4 CLKOUT SGND ENABLE 1 R2 12.1kΩ 1% R1 1kΩ 1% 2 3 1 JU2 R5 1Ω 1% R4 1Ω 1% Q1 R11 105kΩ 1% C5 1000pF C4 0.47μF C3 4.
PAGE 6
Evaluates: MAX16818 MAX16818 Evaluation Kit Figure 2. MAX16818 EV Kit Component Placement Guide— Component Side Figure 3. MAX16818 EV Kit PCB Layout—Component Side Figure 4. MAX16818 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.