LM3207 Datasheet, PDF (1/19 Pages) National Semiconductor (TI) – 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers with Integrated Vref LDO

August 2006
LM3207
650mA Miniature, Adjustable, Step-Down DC-DC
Converter for RF Power Amplifiers with Integrated Vref
LDO
General Description
The LM3207 is a DC-DC converter optimized for powering
WCDMA / CDMA RF power amplifiers (PAs) from a single
Lithium-Ion cell; however they may be used in many other
applications. It steps down an input voltage from 2.7V to
5.5V to a variable output voltage from 0.8V(typ.) to
3.6V(typ.). Output voltage is set using a V_CON analog input
for controlling power levels and efficiency of the RF PA.
The LM3207 also provides a regulated reference voltage(V-
ref) required by linear RF power amplifiers through an inte-
grated LDO with a nominal output voltage of 2.875V and
maximum Iref of 10 mA.
The LM3207 is available in a 9-pin lead free micro SMD
package. High switching frequency (2MHz) allows use of
surface-mount components. Only four small external
surface-mount components are required, an inductor and
three ceramic capacitors.
Features
n 2MHz (typ.) PWM Switching Frequency
n Operates from a single Li-Ion cell (2.7V to 5.5V)
n Variable Output Voltage (0.8V to 3.6V)
n 650mA Maximum load capability
n High Efficiency (95% Typ at 3.9V_IN, 3.4V_OUT at 400mA)
from internal synchronous rectification
n Integrated 2.875V Vref LDO
n Regulated LDO Output up to 10mA max
n Fast 3uS Vref LDO On/Off Time
n 9-pin micro SMD Package
n Current Overload Protection
n Thermal Overload Protection
Applications
n Cellular Phones
n Hand-Held Radios
n RF PC Cards
n Battery Powered RF Devices
Typical Application
FIGURE 1. LM3207 Typical Application
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