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General Description

The MAX16821B evaluation kit (EV kit) is a fully assem-

bled and tested surface-mount printed-circuit board

(PCB) designed to evaluate the MAX16821B pulse-

width-modulation (PWM) LED driver controller in a

boost configuration.

The MAX16821B EV kit operates from a DC supply volt-

age of 7V to 24V. The EV kit’s output is configured to

deliver 660mA of current into series LED string with a

maximum forward voltage of 28V. The LED brightness

can be dimmed using a digital PWM signal.

The EV kit provides an option to configure the

MAX16821B IC’s overvoltage protection, switching fre-

quency, and frequency compensation. The MAX16821B

EV kit also features a clock output PCB pad to drive a

second LED current regulator out-of-phase.

Features

♦ 7V to 24V Input-Voltage Range

♦ 660mA Output Current

♦ Pulse-Width-Modulated LED Current Dimming

♦ Resistor-Adjustable Overvoltage Protection and

Switching Frequency

♦ Clock Output

♦ Fully Assembled and Tested

Evaluates: MAX16821B

MAX16821B Evaluation Kit

________________________________________________________________

Maxim Integrated Products

19-1967; Rev 0; 11/07

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 TYPE

MAX16821BEVKIT+ EV Kit

Denotes lead-free and RoHS-compliant.

DESIGNATION QTY DESCRIPTION

C1, C5, C6 3

10µF±10%, 50V X7S ceramic

capacitors (1210)

Taiyo Yuden UMK325BJHI06K

C2 1

0.1µF±10%, 50V X7R ceramic

capacitor (1206)

Murata GRM319R71H104K

C3, C4 2

1000pF±10%, 25V X7R ceramic

capacitors (0603)

Murata GRM188R71E102K

C7 1

0.022µF±10%, 50V X7R ceramic

capacitor (0603)

Murata GRM188R71H223K

C8 1

4.7µF±10%, 6.3V X7R ceramic

capacitor (0603)

Murata GRM188R70J475K

C9, C10 2

0.1µF±10%, 50V X7R ceramic

capacitors (0603)

Murata GRM188R71H104K

D1 1

3A, 60V Schottky diode (SMA)

Diodes Inc. B360A-13-F

DESIGNATION QTY DESCRIPTION

L1 1

8.8µH, 4A inductor

Sumida CDEP105-8R8

N1–N4 4

60V, 115mA n-channel MOSFETs

(SOT23)

Central Semiconductor 2N7002

LEAD-FREE

N5 1

40V, 4.9A n-channel MOSFET

(8-pin SO)

Vishay Si4446DY

N6 1

60V, 3.2A n-channel MOSFET

(6-pin TSOP)

Vishay Si3458DV-E3

R1 1 249kΩ ±1% resistor (0603)

R2, R5, R10 3 10kΩ ±1% resistors (0603)

R3 0

Not installed, resistor—shorted

(0603)

R4 1 124kΩ ±1% resistor (0603)

R6 1

0.007Ω ±2%, 0.5W sense resistor

(1206)

IRC LRC-LRF1206LF-01-R007-G

Summary of content (5 pages)

PAGE 1
9-1967; Rev 0; 11/07 MAX16821B Evaluation Kit The MAX16821B evaluation kit (EV kit) is a fully assembled and tested surface-mount printed-circuit board (PCB) designed to evaluate the MAX16821B pulsewidth-modulation (PWM) LED driver controller in a boost configuration. The MAX16821B EV kit operates from a DC supply voltage of 7V to 24V. The EV kit’s output is configured to deliver 660mA of current into series LED string with a maximum forward voltage of 28V.
PAGE 2
Evaluates: MAX16821B MAX16821B Evaluation Kit Component List (continued) DESIGNATION R7 QTY 1 DESCRIPTION DESIGNATION QTY R13 1 1kΩ ±1% resistor (0603) U1 1 Maxim PWM LED driver controller MAX16821BATI+ (28-pin thin QFN-EP*, 5mm x 5mm x 0.8mm) — 1 PCB: MAX16821B Evaluation Kit+ 0.15Ω ±1%, 0.5W sense resistor (1206) IRC LRC-LRC1206LF-01-R150-F R8 1 1Ω ±5% resistor (0603) R9 1 2kΩ ±1% resistor (0603) R11 1 2.49kΩ ±1% resistor (0603) R12 1 1.
PAGE 3
MAX16821B Evaluation Kit LED+ exceeds the programmed 33V threshold, the low-side driver turns off to prevent current through the LED string connected between LED+ and LED-. Use the following equation to calculate R1 and R2 resistor values for a new overvoltage threshold: R1 = R2 × 100mV R7 = ILED where 100mV is the MAX16821B regulated SENSE+ to SENSE- differential current-sense voltage and ILED is the desired LED current.
PAGE 4
Evaluates: MAX16821B MAX16821B Evaluation Kit R5 10kΩ 1% EN VIN VIN VCC SGND 15 R13 1kΩ 1% 16 3 3 EN N.C. OVI U1 DH N3 R12 1.24kΩ 1% 3 1 LX MAX16821B 17 N4 R11 2.49kΩ 1% SGND 7 VIN BST 6 LED+ L1 8.8μH 5 4 2 D1 5, 6, 7, 8 18 2 2 CLP 2 C10 0.1μF CLKOUT 9 EP N2 2 PWMDIM CLKOUT N.C. 1 1 PWMDIM I.C. 19 20 PGND 8 C3 1000pF R2 10kΩ 1% VCC 14 10 MODE R1 249kΩ 1% 11 12 RT/SYNC R3 SHORTED OUTV 13 LED+ SGND R4 124kΩ 1% OUTV C1 10μF 50V C2 0.
PAGE 5
MAX16821B Evaluation Kit Figure 3. MAX16821B EV Kit PCB Layout—Component Side Figure 4. MAX16821B 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.