LM3279
www.ti.com
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
a given input voltage and is particularly suitable for
Power Amplifiers operating from single-cell Li-Ion
batteries in portable applications.
High-Efficiency PFM and PWM Modes with
Internal Seamless Transition
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Operates from a Single Li-Ion Cell: 2.7V to 5.5V
Adjustable Output Voltage:
The LM3279 has four modes of operation: Pulse
Width Modulation (PWM), Pulse Frequency
Modulation (PFM), standby, and shutdown. During
normal conditions, the LM3279 operates in full
synchronous PWM mode at 2.4 MHz typical switching
frequency, providing seamless transitions between
buck and boost operating regimes. Energy-saving
PFM mode increases efficiencies and current savings
during low-power RF transmission modes. For high-
transmit power, the device operates in PWM buck or
boost mode, whereas the device can transition
between PWM and PFM modes during low-power
transmit. The LM3279 can be controlled either via an
included MIPI® RFFE Digital Control Interface or by
using an analog control from an external MCU,
offering design flexibility.
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RFFE Digital Control: 0.4V to 4.2V
Analog Control: 0.6V to 4.2V
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1A Maximum Load Capability for VBATT ≥ 3.2V,
VOUT = 3.6V
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2.4 MHz (typ.) Switching Frequency
Seamless Buck-Boost Mode Transition
Fast Output Voltage Transition: 0.8V to 4.0V in
20 µs
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High-Efficiency: 95% typ. at VBATT = 3.7V,
VOUT = 3.3V, at 300 mA
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Input Over-Current Limit
Output Over-Voltage Clamp
Internal Compensation
The power converter topology enables minimum total
solution size by using one small footprint and case
size inductor and two surface mount capacitors.
16-bump DSBGA Package
APPLICATIONS
The LM3279 is internally compensated for buck and
boost modes of operation thus providing an optimal
transient response.
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3G/4G Smartphones
RF PC Cards
The LM3279 is available in a small 16-bump lead-free
DSBGA package of size 2.121 mm x 2.504 mm.
Tablets, eBooks Readers
Battery-Powered RF Devices
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
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