SNOSB38B – JANUARY 2009 – REVISED APRIL 2013
LM3241 6MHz, 750mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power
Amplifiers
Check for Samples:
1
FEATURES
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
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.
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APPLICATIONS
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Battery-Powered 3G/4G Power Amplifiers
Hand-Held Radios
RF PC Cards
Battery-Powered RF Devices
TYPICAL APPLICATION
V
IN
2.7V to 5.5V
V
OUT
VIN
SW
10
PF
EN
V
OUT
= 2.5 x VCON
0.47
PH
0.6V to 3.4V
LM3241
VCON
GND
FB
4.7
PF
1
2
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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Copyright © 2009–2013, Texas Instruments Incorporated
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.
TI [ TEXAS INSTRUMENTS ]
