3 A, 2 MHz Buck-Regulating LED Driver

A6210

3

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Reg

Ref

+

–

Control

Logic

On

Timer

Regulator

Comparator

Off

Timer

Driver

Linear

Regulator

Fault

VIN UVLO

TSD

Linear OK

VIN

DIS

GND

TON

BOOT

LX

ISEN

Sleep

Circuit

SGND

Switch

Closed = On

NC

C1

1.0 μF

C2

L1

68 μH

D1

R2

390 mΩ

Blank

Top-off

Charge

Pump

22 nF

R1

180 kΩ

Switching Frequency = 1.4 MHz

All capacitors are X5R or X7R ceramic

Resistor R2 should be surface mount, low inductance type, rated at 250 mW at 70°C

LED1

LED2

LED3

Functional Block Diagram

Pin-out Diagram

Terminal List Table

Number

Name

Function

1

VIN

Input supply

2, 7, 13, 14,

15, 16

NC

No connection; tie to GND

3

TON

Terminal for on-time setting with external resistor

4, 5, 6

GND

Ground terminal

8

ISEN

Current sense input

9

SGND

Current sense ground reference

10

DIS

Disable/enable logic input; active high

11

BOOT

Bootstrap supply node

12

LX

Switch node

–PAD

Exposed thermal pad; connect to ground plane

(GND) by through-hole vias

12

11

10

9

1

2

3

4

LX

BOOT

DIS

SGND

PAD

VIN

NC

TON

GND

(Top View)