LT3480

1

3480fe

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

36V, 2A, 2.4MHz Step-Down

Switching Regulator with

70µA Quiescent Current

The LT®3480 is an adjustable frequency (200kHz to

2.4MHz) monolithic buck switching regulator that ac-

cepts input voltages up to 36V (60V maximum). A high

efficiency 0.25 switch is included on the die along with

a boost Schottky diode and the necessary oscillator, con-

trol, and logic circuitry. Current mode topology is used

for fast transient response and good loop stability. Low

ripple Burst Mode operation maintains high efficiency at

low output currents while keeping output ripple below

15mV in a typical application. In addition, the LT3480 can

further enhance low output current efficiency by draw-

Shutdown reduces input supply current to less than 1µA

while a resistor and capacitor on the RUN/SS pin provide a

controlled output voltage ramp (soft-start). A power good

output voltage. The LT3480 is available in 10-lead MSOP

and 3mm

× 3mm DFN packages with exposed pads for

low thermal resistance.

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Wide Input Range:

Operation from 3.6V to 36V

Over-Voltage Lockout Protects Circuits

through 60V Transients

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2A Maximum Output Current

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Output Ripple < 15mV

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Adjustable Switching Frequency: 200kHz to 2.4MHz

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Integrated Boost Diode

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Synchronizable Between 250kHz to 2MHz

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Power Good Flag

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Saturating Switch Design: 0.25 On-Resistance

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0.790V Feedback Reference Voltage

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Output Voltage: 0.79V to 20V

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Soft-Start Capability

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Small 10-Lead Thermally Enhanced MSOP and

(3mm

× 3mm) DFN Packages

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Automotive Battery Regulation

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Power for Portable Products

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Distributed Supply Regulation

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Industrial Supplies

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

Burst Mode is a registered trademark of Linear Technology Corporation. All other

trademarks are the property of their respective owners.

3.3V Step-Down Converter

SW

FB

PG

RT

BD

4.5V TO 36V

TRANSIENT

TO 60V

3.3V

2A

4.7µF

0.47µF

470pF

22µF

100k

14k

40.2k

4.7µH

316k

GND

OFF ON

LT3480

3480 TA01

RUN/SS

BOOST

SYNC

Efficiency

LOAD CURRENT (A)

0

50

0.5

1.0

1.5

2

3480 TA01b

60

100

90

80

70

L = 5.6µH

F = 800 kHz