LM3279 Datasheet, PDF (1/31 Pages) Texas Instruments – LM3279 Buck-Boost Converter with MIPI RFFE Interfacefor 3G and 4G RF Power Amplifiers

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
FEATURES
1
•2 MIPI® RFFE Digital Control Interface
• High-Efficiency PFM and PWM Modes with
Internal Seamless Transition
• Operates from a Single Li-Ion Cell: 2.7V to 5.5V
• Adjustable Output Voltage:
– RFFE Digital Control: 0.4V to 4.2V
– Analog Control: 0.6V to 4.2V
• 1A Maximum Load Capability for V_BATT ≥ 3.2V,
V_OUT = 3.6V
• 2.4 MHz (typ.) Switching Frequency
• Seamless Buck-Boost Mode Transition
• Fast Output Voltage Transition: 0.8V to 4.0V in
20 µs
• High-Efficiency: 95% typ. at V_BATT = 3.7V,
V_OUT = 3.3V, at 300 mA
• Input Over-Current Limit
• Output Over-Voltage Clamp
• Internal Compensation
• 16-bump DSBGA Package
APPLICATIONS
• 3G/4G Smartphones
• RF PC Cards
• Tablets, eBooks Readers
• Battery-Powered RF Devices
DESCRIPTION
The LM3279 is a buck-boost DC/DC converter
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.
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.
The power converter topology enables minimum total
solution size by using one small footprint and case
size inductor and two surface mount capacitors.
The LM3279 is internally compensated for buck and
boost modes of operation thus providing an optimal
transient response.
The LM3279 is available in a small 16-bump lead-free
DSBGA package of size 2.121 mm x 2.504 mm.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
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
necessarily include testing of all parameters.
Copyright © 2013, Texas Instruments Incorporated