LTC3210-1

1

32101fc

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

Protected by US Patents including 6411531.

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Multi-LED Light Supply for Cellphones/DSCs/PDAs

MAIN/CAM LED Controller

with 64-Step Brightness Control

in 3mm

× 3mm QFN

verter designed to drive four MAIN LEDs and one high

current CAM LED for camera lighting. The LTC3210-1

requires only four small ceramic capacitors and two cur-

rent set resistors to form a complete LED power supply

and current controller.

Built-in soft-start circuitry prevents excessive inrush cur-

rent during start-up and mode changes. High switching

frequency enables the use of small external capacitors.

Independent MAIN and CAM full-scale current settings

are programmed by two external resistors.

Shutdown mode and current output levels are selected

via two logic inputs. ENM and ENC are toggled to adjust

the LED currents via internal counters and DACs. A 6-bit

linear DAC (64 steps) provides high resolution brightness

control for the MAIN display.

The charge pump optimizes efficiency based on the volt-

age across the LED current sources. The part powers up

in 1x mode and will automatically switch to boost mode

whenever any enabled LED current source begins to enter

dropout. The LTC3210-1 is available in a 3mm

× 3mm

16-lead QFN package. Standard (0.75mm) and ultra-thin

(0.55mm) package profiles are available.

C1P

C1M

C2P

RM

RC

GND

C2M

CPO

MLED1

MLED2

MLED3

MLED4

CLED

ENM

ENC

LTC3210-1

C1

2.2μF

C2

2.2μF

C3

2.2μF

30.1k

1%

24.3k

1%

ENM

ENC

C4

2.2μF

32101 TA01

MAIN

CAM

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Low Noise Charge Pump Provides High Efficiency

with Automatic Mode Switching

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Multimode Operation: 1x, 1.5x, 2x

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Individual Full-Scale Current Set Resistors

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Up to 500mA Total Output Current

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Single Wire EN/Brightness Control for MAIN and

CAM LEDs

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64:1 Linear Brightness Control Range for

MAIN Display

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Four 25mA Low Dropout MAIN LED Outputs

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One 400mA Low Dropout CAM LED Output

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Low Noise Constant Frequency Operation

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Low Shutdown Current: 3μA

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Internal Soft-Start Limits Inrush Current During

Startup and Mode Switching

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Open/Short LED Protection

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No Inductors

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3mm

× 3mm 16-Lead Plastic QFN Packages with

0.55mm and 0.75mm Profiles

3.0

60

80

100

32101 TA01b

40

20

50

70

90

30

10

0

3.6

3.8

3.2

4.0

3.4

4.4

4.2

4 LEDs AT 9mA/LED

4-LED MAIN Display

TYPICAL APPLICATION

DESCRIPTION

FEATURES

APPLICATIONS