LM3208 Datasheet, PDF (1/25 Pages) National Semiconductor (TI) – 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers

LM3208
www.ti.com
SNVS404B – APRIL 2006 – REVISED MARCH 2013
LM3208 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power
Amplifiers
Check for Samples: LM3208
FEATURES
1
•2 2 MHz (typ.) PWM Switching Frequency
• Operates from a Single Li-Ion Cell (2.7V to
5.5V)
• Adjustable Output Voltage (0.8V to 3.6V)
• Fast Output Voltage Transient (0.8V to 3.4V in
25µs typ.)
• 650mA Maximum Load Capability
• High Efficiency (95% typ. at 3.9V_IN, 3.4V_OUT at
400mA)
• 8-pin DSBGA Package
• Current Overload Protection
• Thermal Overload Protection
APPLICATIONS
• Cellular Phones
• Hand-Held Radios
• RF PC Cards
• Battery Powered RF Devices
DESCRIPTION
The LM3208 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 in
the range from 2.7V to 5.5V to an adjustable output
voltage of 0.8V to 3.6V. Output voltage is set by
using a V_CON analog input to control power levels and
efficiency of the RF PA.
The LM3208 offers superior performance for mobile
phones and similar RF PA applications. Fixed-
frequency PWM operation minimizes RF interference.
A shutdown function turns the device off and reduces
battery consumption to 0.01 µA (typ.).
The LM3208 is available in an 8-pin lead-free DSBGA
package. A high switching frequency (2 MHz typ.)
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
LM3208
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. LM3208 Typical Application
1
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.
All trademarks are the property of their respective owners.
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.
Copyright © 2006–2013, Texas Instruments Incorporated