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LTC1430

High Power Step-Down

Switching Regulator Controller

The LTC

regulator controller optimized for 5V to 3.xV applications.

It includes a precision internal reference and an internal

feedback system that can provide output regulation of

±1%

over temperature, load current and line voltage shifts. The

LTC1430 uses a synchronous switching architecture with

two N-channel output devices, eliminating the need for a

high power, high cost P-channel device. Additionally, it

senses output current across the drain-source resistance

of the upper N-channel FET, providing an adjustable

current limit without an external low value sense resistor.

The LTC1430 includes a fixed frequency PWM oscillator for

low output ripple under virtually all operating conditions.

The 200kHz free-running clock frequency can be externally

adjusted from 100kHz to above 500kHz. The LTC1430

features low 350

µA quiescent current, allowing greater

than 90% efficiency operation in converter designs from

1A to greater than 50A output current. Shutdown mode

drops the LTC1430 supply current to 1

µA.

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High Power 5V to 3.xV Switching Controller:

Can Exceed 10A Output

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All N-Channel External MOSFETs

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Constant Frequency Operation—Small Inductor

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Excellent Output Regulation:

±1% Over Line, Load

and Temperature Variations

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High Efficiency: Over 95% Possible

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Fixed Frequency Operation

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No Low Value Sense Resistor Needed

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Outputs Can Drive External FETs with Up to

10,000pF Gate Capacitance

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Quiescent Current: 350

µA Typ, 1µA in Shutdown

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Fast Transient Response

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Adjustable or Fixed 3.3V Output

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Available in 8- and 16-Lead PDIP and SO Packages

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

LOAD CURRENT (A)

40

70

100

90

80

50

60

10

LTC1430 • TA02

0.1

1

Efficiency

+

220

µF

×4

330

µF

×6

+

+

+

L1, 2.8

µH

FREQSET

SHDN

COMP

SS

PGND

GND

G1

G2

NC

LTC1430 • TA01

SHUTDOWN

FB

NC

L1: ETQP6F1R6SFA

M1A, M1B, M2: MOTOROLA MTD20N03HL

LTC1430

16k

100

Ω

7.5k

4700pF

C1

220pF

1N4148

1k

0.1

µF

1

µF

0.01

µF

0.1

µF

4.7

µF

0.1

µF

3.3V

10A

M1A, M1B

2 IN PARALLEL

M2

Typical 5V to 3.3V, 10A Application

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Power Supply for P6 and Pentium

®

Microprocessors

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High Power 5V to 3.xV Regulators

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Local Regulation for Dual Voltage Logic Boards

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Low Voltage, High Current Battery Regulation

Pentium is a registered trademark of Intel Corporation.

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO