LTC3315B

1

Rev. 0

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TYPICAL APPLICATION

FEATURES

DESCRIPTION

Dual 5V, 2A Synchronous Step-Down

DC/DCs in 2mm

× 2mm LQFN

The LTC®3315B features dual 2A monolithic synchro-

nous step-down converters operating from a 2.25V to

5.5V input supply in one package for space-constrained

applications with demanding performance requirements.

Using constant frequency, peak current mode control at

switching frequencies up to 10MHz with a minimum on-

time as low as 25ns, both bucks achieve high efficiency

and fast transient response in a very small application

footprint.

The LTC3315B operates in forced continuous or pulse

high efficiency at light loads. The common buck switching

frequency is 6MHz and can be synchronized to an external

oscillator via the MODE/SYNC pin.

The LTC3315B can regulate outputs as low as 500mV.

Other features include precision enable thresholds, a

PGOOD signal, output overvoltage protection, thermal

shutdown, output short-circuit protection, and up to 100%

duty cycle operation for low dropout. The LTC3315B is

available in a compact 2mm × 2mm LQFN package.

Efficiency vs Load Current

Dual 6MHz 2A Buck Regulators

APPLICATIONS

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Dual Outputs Each with 2A Output Current

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High Efficiency: 19mΩ NMOS and 75mΩ PMOS

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Wide Bandwidth, Fast Transient Response

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Switching Frequency Synchronizable Up to 10MHz

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Peak Current Mode Control

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Minimum On-Time: 25ns

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Safely Tolerates Inductor Saturation in Overload

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Shutdown Current: 1.2µA

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Precision 400mV Enable Thresholds

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Internal Soft-Start and Compensation

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Power Good Output

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Low Profile, Thermally Enhanced 12-Lead

2mm × 2mm × 0.74mm LQFN Package

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AEC-Q100 Qualified for Automotive Applications

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Servers, Telecom Supplies, Optical Networking

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Distributed DC Power Systems (POL)

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FPGA, ASIC, µP Core Supplies

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Industrial/Automotive/Communications

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330nH

10µF

86.6k

33.2k

3.3pF

10µF

330nH

100k

33.2k

10µF

10µF

3.3pF

SW1

FB1

SW2

FB2

PGOOD

3315B TA01a

EN2

MODE/SYNC

GND

EN1

LTC3315B

3.3V

1.8V, 2A

2.0V, 2A

1µF

0201

1µF

0201

Burst Mode OPERATION

L = 330nH, L DCR = 21mΩ

EFFICIENCY

POWER LOSS

LOAD CURRENT (A)

1m

10m

100m

1 2

0

10

20

30

40

50

60

70

80

90

100

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Efficiency vs Load Current

3315B G01