LTC3528/LTC3528B

1

3528fa

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

1A, 1MHz Synchronous

Step-Up DC/DC Converters

in 3mm × 2mm DFN

The LTC

step-up DC/DC converters with output disconnect. High

efficiency synchronous rectification, in addition to a 700mV

start-up voltage and operation down to 500mV once

started, provides longer run-time for single or multiple

cell battery-powered products.

A switching frequency of 1MHz minimizes solution foot-

print by allowing the use of tiny, low profile inductors and

ceramic capacitors. The current mode PWM is internally

compensated, simplifying the design process. The LTC3528

enters Burst Mode operation at light loads, while the

LTC3528B features continuous switching at light loads.

Anti-ringing circuitry reduces EMI by damping the inductor

in discontinuous mode. Additional features include a low

shutdown current, open-drain power good output, short-

circuit protection and thermal overload protection.

The LTC3528/LTC3528B are offered in an 8-lead 3mm ×

2mm × 0.75mm DFN package.

■

Delivers 3.3V at 200mA from a Single Alkaline/

NiMH Cell or 3.3V at 400mA from Two Cells

■

■

■

Up to 94% Efficiency

■

Output Disconnect

■

1MHz Fixed Frequency Operation

■

■

Integrated Soft-Start

■

Current Mode Control with Internal Compensation

■

Burst Mode

(LTC3528)

■

Low Noise PWM Operation (LTC3528B)

■

Internal Synchronous Rectifier

■

Logic Controlled Shutdown: <1μA

■

Anti-Ringing Control

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Low Profile (3mm × 2mm × 0.75mm) DFN Package

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Medical Instruments

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Flash-Based MP3 Players

■

Noise Canceling Headphones

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Wireless Mice

■

Bluetooth Headsets

, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology

Corporation. All other trademarks are the property of their respective owners.

SW

499k

4.7μH

287k

4.7μF

10μF

33pF

3528 TA01a

LTC3528

SHDN

PGOOD

FB

1.8V TO 3.2V

3.3V

400mA

OFF ON

GND

LOAD CURRENT (mA)

0.01

80

90

100

100

3528 TA01b

70

60

0.1

1

10

1000

50

40

30

100

1000

10

1

0.1

0.01

EFFICIENCY

POWER LOSS

Efficiency and Power Loss