LM3205_15 Datasheet, PDF (1/28 Pages) Texas Instruments – LM3205 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers

LM3205
www.ti.com
SNVS388E – JULY 2005 – REVISED APRIL 2013
LM3205 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power
Amplifiers
Check for Samples: LM3205
FEATURES
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•2 2 MHz (typ.) PWM Switching Frequency
• Operates from a Single Li-Ion Cell (2.7V to
5.5V)
• Variable Output Voltage (0.8V to 3.6V)
• Fast Output Voltage Transient (0.8V to 3.6V in
20µs)
• 650mA Maximum Load Capability
• High Efficiency (96% Typ at 4.2V_IN, 3.4V_OUT at
400mA) from Internal Synchronous
Rectification
• Current Overload Protection
• Thermal Overload Protection
• Packages
– 8-Pin DSBGA (Lead Free)
• 10-Pin WSON
APPLICATIONS
• Cellular Phones
• Hand-Held Radios
• RF PC Cards
• Battery Powered RF Devices
DESCRIPTION
The LM3205 is a DC-DC converter optimized for
powering 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 LM3205 offers superior performance for mobile
phones and similar RF PA applications. Fixed-
frequency PWM operation minimizes RF interference.
Shutdown function turns the device off and reduces
battery consumption to 0.01 µA (typ.).
The LM3205 is available in DSBGA package and
WSON package. For all other package options
contact your local TI sales office.
A high switching frequency (2 MHz) 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
PV_IN
EN
V_DD
SW
LM3205
FB
V_{CON PGND SGND}
3.3 PH
V_OUT
0.8V to 3.6V
V_OUT = 2.5 x V_CON
4.7 PF
Figure 1. LM3205 Typical Application
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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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