LM3241_13 Datasheet, PDF (1/23 Pages) Texas Instruments – LM3241 6MHz, 750mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers

LM3241
www.ti.com
SNOSB38B – JANUARY 2009 – REVISED APRIL 2013
LM3241 6MHz, 750mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power
Amplifiers
Check for Samples: LM3241
FEATURES
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•2 6MHz (typ.) PWM Switching Frequency
• Operates from a Single Li-Ion Cell (2.7V to
5.5V)
• Adjustable Output Voltage (0.6V to 3.4V)
• 750 mA Maximum Load Capability
• High Efficiency (95% typ. at 3.9V_IN, 3.3V_OUT at
500 mA)
• Automatic ECO/PWM mode change
• 6-bump DSBGA Package
• Current Overload Protection
• Thermal Overload Protection
• Soft Start Function
• C_IN and C_OUT are 0402 (1005) case size and
6.3V of rated-voltage ceramic capacitor
• Small Chip Inductor in 0805 (2012) case size
APPLICATIONS
• Battery-Powered 3G/4G Power Amplifiers
• Hand-Held Radios
• RF PC Cards
• Battery-Powered RF Devices
DESCRIPTION
The LM3241 is a DC-DC converter optimized for
powering RF power amplifiers (PAs) from a single
Lithium-Ion cell; however, it may be used in many
other applications. It steps down an input voltage
from 2.7V to 5.5V to an adjustable output voltage
from 0.6V to 3.4V. Output voltage is set using a
VCON analog input for controlling power levels and
efficiency of the RF PA.
The LM3241 offers three modes of operation. In
PWM mode the device operates at a fixed frequency
of 6MHz (typ.) which minimizes RF interference when
driving medium-to-heavy loads. At light load, the
device enters into ECO mode automatically and
operates with reduced switching frequency. In ECO
mode, the quiescent current is reduced and extends
the battery life. Shutdown mode turns the device off
and reduces battery consumption to 0.1 µA (typ.).
The LM3241 is available in a 6-bump lead-free
DSBGA package. A high-switching frequency (6MHz)
allows use of tiny surface-mount components. Only
three small external surface-mount components, an
inductor and two ceramic capacitors are required.
TYPICAL APPLICATION
V_IN
2.7V to 5.5V
10 PF
VIN
EN
VCON
LM3241
GND
0.47 PH
SW
FB
4.7 PF
V_OUT
0.6V to 3.4V
V_OUT = 2.5 x VCON
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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.
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