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LTC3202

3202fa

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

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White LED Backlighting

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Programmable Boost Current Source

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Low Noise Constant Frequency Operation

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25% Less Input Current Than Doubler Charge Pump

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High Output Current: Up To 125mA

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Small Application Circuit

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Regulated Output Voltage or Current

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Automatic Soft-Start

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No Inductors

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1.5MHz Switching Frequency

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Available in 10-Pin MSOP and 3mm

× 3mm

DFN Packages

Low Noise, High Efficiency

Charge Pump for White LEDs

The LTC

pump DC/DC converter that uses fractional conversion to

increase efficiency in white LED applications. The part can

be used to produce a regulated voltage or current of up to

125mA from a 2.7V to 4.5V input. Low external parts count

(two flying capacitors and two small bypass capacitors at

battery-powered applications.

An internal 2-bit DAC allows LED current to be adjusted for

LED brightness control. The LTC3202 also has thermal

shutdown protection and can survive a continuous short-

prevents excessive inrush current during start-up. High

switching frequency enables the use of small external

capacitors. A low current shutdown feature disconnects

than1

µA.

The LTC3202 is available in the 10-pin MSOP and 3mm

×

3mm DFN packages.

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

Programmable White LED Power Supply

3202 TA01

LTC3202

FB

GND

C4

1

µF

C1

1

µF

5, 11

3

2

CURRENT

PROGRAMMING

3V TO 4.5V

10

4

1

36

Ω

36

Ω

36

Ω

36

Ω

36

Ω

36

Ω

C3

1

µF

C2

1

µF

D0

D1

8

7

96

C1, C2, C3, C4 = MURATA GRM 39X5R105K6.3 OR TAIYO YUDEN JMK107BJ105MA

0mA TO 125mA

TOTAL CURRENT

(AC COUPLED)

20mV/DIV

(AC COUPLED)

20mV/DIV

500ns/DIV

3202 G09

Input and Output Ripple