LT3980

1

3980fa

For more information www.linear.com/LT3980

58V, 2A, 2.4MHz

Step-Down Switching Regulator

with 85µA Quiescent Current

The LT®3980 is an adjustable frequency (100kHz to

2.4MHz) monolithic buck switching regulator that accepts

input voltages up to 58V (80V transient). A high efficiency

200mΩ switch is included on the die along with a boost

Schottky diode and the necessary oscillator, control, and

logic circuitry. Current mode topology is used for fast

transient response and good loop stability. Catch diode

current sense (DA pin) protects the circuit during input

voltage transients even when a high switching frequency

is used. 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

LT3980 can further enhance low output current efficiency

above 3V. 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).

the programmed output voltage. The LT3980 is available

in 16-pin MSOP and 3mm

× 4mm DFN packages with

exposed pads for low thermal resistance.

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Automotive Battery Regulation

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Distributed Supply Regulation

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Industrial Supplies

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Wall Transformer Regulation

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Wide Input Range: Operation from 3.6V to 58V

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Overvoltage Lockout Protects Circuits Through 80V

Transients

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2A Maximum Output Current

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Adjustable Switching Frequency: 100kHz to 2.4MHz

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Catch Diode Current Sense Protects Circuit Through

Short-Circuit and Input Overvoltage

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Synchronizable Between 250kHz to 2MHz

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Power Good Flag

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Saturating Switch Design: 200mΩ On-Resistance

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Thermal Protection

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Soft-Start Capability

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Small 16-Pin Thermally Enhanced MSOP and

3mm

× 4mm DFN Packages

5V Step-Down Converter

Typical applicaTion

DescripTion

FeaTures

applicaTions

SW

FB

PG

RT

BD

6.5V TO 58V

TRANSIENT

TO 80V

5V

2A

10µF

0.47µF

1nF

47µF

100k

4.75k

97.6k

10µH

22pF

536k

GND

DA

OFF ON

LT3980

3980 TA01

RUN/SS

BOOST

SYNC

L

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

of Linear Technology Corporation. All other trademarks are the property of their respective

owners.

0

0.5

1

2

3980 TA01b

1.5

f = 400kHz

D = DIODES, INC. SBR3U100LP

85

70

60

55

50

95

90

80

75

65