LM3291
www.ti.com
SNVSA12 –SEPTEMBER 2013
LM3291 Product Brief
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FEATURES
DESCRIPTION
The LM3291 is a high-speed linear amplifier that, with
its companion IC LM3290, constitutes an RF
Envelope Modulator (EM) for supplying 3G/4G Power
Amplifiers (PA) in envelope tracking systems. The
amplifier provides extremely low output impedance
and low output noise over a wide bandwidth.
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Highly Programmable High-Current Linear
Amplifier
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> 75 MHz Typical Small Signal Bandwidth
Extremely Low Output Impedance
High Linearity
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In conjunction with an Envelope Tracking (ET)
capable RFIC and PA, the LM3291 and LM3290
greatly improve PA efficiency for 3G and LTE
operation.
Differential Analog Input Compatible with
eTrak 1.0 Standard
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Low Output Noise
When paired with the LM3290 provides a
complete Envelope Modulator solution for
3G/4G Envelope Tracking Power Amplifiers.
In ET mode, the LM3291 and LM3290 provide
envelope tracking supply voltage for the PA
maximizing total EM + PA efficiency. The envelope
modulator follows the differential envelope reference
input signal delivered by the RFIC to the LM3291.
The output is a single-ended dynamic power supply
voltage to the PA.
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Automatically controlled through LM3290 in an
envelope modulation solution using MIPI®
RFFE 1.1-compatible interface.
APPLICATIONS
The LM3291 supports 3G and LTE operation up to 20
MHz signal bandwidth.
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3G/LTE Handsets
3G//LTE Tablets
The LM3291’s programmable parameters are
controlled by LM3290 via a direct serial interface
between the two devices. No additional controls are
needed in the system. This interface provides flexible
control and adjustment options to optimize LM3291
efficiency and noise performance for various
frequency bands and power levels.
3G/LTE Data Cards and Wireless Modems
MIPI eTrak
2.5V - 5V
BATTERY
LM3291
At high TX output power, the EM can be operated in
ET mode where LM3290 and LM3291 together
modulate the supply of the PA with the envelope
signal to improve overall system efficiency. At low TX
output power, the EM can be transitioned to Average
Power Tracking (APT) mode where LM3291 is placed
into shutdown mode to improve system efficiency.
LM3290
RFIC
or
L
C
BBIC
The LM3291 is available in a 12-pin lead-free DSBGA
package.
For the full datasheet, samples, or the EVM
hardware and software please contact
representative at ET@list.ti.com.
a TI
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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.
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MIPI is a registered trademark of Mobile Industry Processor Interface Alliance.
All other trademarks are the property of their respective owners.
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