LTC7149

1

7149fa

For more information www.linear.com/LTC7149

TYPICAL APPLICATION

FEATURES

DESCRIPTION

The LTC®7149 is a high efficiency 60V, 4A synchronous

monolithic step-down regulator for inverting output

applications. The regulator features a single resistor-

programmable output voltage and high efficiency over a

The inverting regulator operates from an input voltage

range of 3.4V to 60V and provides an adjustable output

from (–28V) to zero volts while delivering up to 4A of

inductor current. The switching frequency is also set

with an external resistor. A user-selectable mode input is

provided to allow the user to trade off ripple noise for ef-

ficiency at light loads; Burst Mode operation provides the

highest efficiency at light loads, while forced continuous

mode provides low output ripple. The MODE/SYNC pin

can also be used to synchronize the switching frequency

to an external clock. Internal level-shift circuits allow the

I/O pins (RUN, MODE/SYNC, PGOOD) to be referenced

to board GND.

The LTC7149 operates with a peak current mode architec-

ture that allows for fast transient response with inherent

cycle-to-cycle current limit protection.

APPLICATIONS

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n

n

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Integrated 110m Top N-Channel/50m Bottom

N-Channel MOSFETs

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Board GND Referenced I/O Pins (RUN, PGOOD,

MODE/SYNC)

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Accurate Resistor Programmable

Frequency (300kHz to 3MHz) with ±50%

Frequency SyncRange

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±0.8% Output Voltage Accuracy

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Peak Current Mode Operation

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Programmable Soft-Start

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Overtemperature Protection

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Available in 28-Lead (4mm x 5mm) QFN and

TSSOPPackages

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Industrial Applications

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Telecom Power Supplies

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Distributed Power Systems

All registered trademarks and trademarks are the property of their respective owners. Protected

by U.S. Patents, including 5481178, 5705919, 5847554, 6580258.

0

0.5

1

1.5

2

2.5

3

3.5

4

70

75

80

85

90

95

100

7149 TA01b

–5V

3.3A

+

LTC7149

7149 TA01

RUN

GND

ITH

SW

BOOST

MODE/SYNC

ISET

22µF

22µF × 2

2.2µF

0.1µF

100k

10nF

0.1µF

200k

6.8µH

24V

1k

4.7nF

100pF

150F

60V, 4A Synchronous

Step-Down Regulator for

Inverting Outputs