LM3279

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SNVS970A – MARCH 2013 – REVISED MAY 2013

LM3279 Buck-Boost Converter with MIPI® RFFE Interface

for 3G and 4G RF Power Amplifiers

Check for Samples: LM3279

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FEATURES

DESCRIPTION

The LM3279 is a buck-boost DC/DC converter

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MIPI® RFFE Digital Control Interface

designed to generate output voltages above or below

•

High-Efficiency PFM and PWM Modes with

a given input voltage and is particularly suitable for

Internal Seamless Transition

Power Amplifiers operating from single-cell Li-Ion

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Operates from a Single Li-Ion Cell: 2.7V to 5.5V

batteries in portable applications.

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Adjustable Output Voltage:

The LM3279 has four modes of operation: Pulse

Width

Modulation

(PWM),

Pulse

Frequency

–

RFFE Digital Control: 0.4V to 4.2V

Modulation (PFM), standby, and shutdown. During

–

Analog Control: 0.6V to 4.2V

normal conditions, the LM3279 operates in full

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synchronous PWM mode at 2.4 MHz typical switching

frequency, providing seamless transitions between

buck and boost operating regimes. Energy-saving

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2.4 MHz (typ.) Switching Frequency

PFM mode increases efficiencies and current savings

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Seamless Buck-Boost Mode Transition

during low-power RF transmission modes. For high-

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Fast Output Voltage Transition: 0.8V to 4.0V in

transmit power, the device operates in PWM buck or

20 µs

boost mode, whereas the device can transition

between PWM and PFM modes during low-power

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transmit. The LM3279 can be controlled either via an

included MIPI® RFFE Digital Control Interface or by

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Input Over-Current Limit

using an analog control from an external MCU,

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Output Over-Voltage Clamp

offering design flexibility.

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Internal Compensation

The power converter topology enables minimum total

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16-bump DSBGA Package

solution size by using one small footprint and case

size inductor and two surface mount capacitors.

APPLICATIONS

The LM3279 is internally compensated for buck and

boost modes of operation thus providing an optimal

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3G/4G Smartphones

transient response.

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RF PC Cards

The LM3279 is available in a small 16-bump lead-free

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Tablets, eBooks Readers

DSBGA package of size 2.121 mm x 2.504 mm.

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Battery-Powered RF Devices

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PRODUCTION DATA information is current as of publication date.

Copyright © 2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.