LM3203 Datasheet, PDF (1/23 Pages) National Semiconductor (TI) – Step-Down DC-DC Converter with Bypass Mode for CDMA / WCDMA RF Power Amplifiers

LM3203
www.ti.com
SNVS355C – MAY 2005 – REVISED JULY 2005
LM3203 Step-Down DC-DC Converter with Bypass Mode for CDMA / WCDMA RF Power
Amplifiers
Check for Samples: LM3203
FEATURES
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•2 2MHz (typ.) PWM Switching Frequency
• Operates from a single Li-Ion cell (2.7V to
5.5V)
• Adjustable Output Voltage (0.8V to 3.6V)
• 500mA Maximum load capability (PWM and
Bypass mode)
• PWM / Forced Bypass Mode
• Low R_DSON Bypass FET: 85mΩ (typ.)
• High Efficiency (96% typ. at 3.6V_IN, 3.2V_OUT at
150mA)
• Fast Turn-on time when Enabled (50µs typ.),
3GPP Compliant
• 10-pin micro SMD Package
• Current Overload Protection
• Thermal Overload Protection
APPLICATIONS
• Cellular Phones
• Hand-Held Radios
• RF PC Cards
• Battery Powered RF Devices
DESCRIPTION
The LM3203 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 of 2.7V to 5.5V to an
adjustable output voltage of 0.8V to 3.6V. The output voltage is set using a V_CON analog input and external
resistor dividers for optimizing efficiency of the RF PA at various power levels.
The LM3203 offers 3 modes for mobile phones and similar RF PA applications. Fixed-frequency PWM mode
minimizes RF interference. Bypass mode turns on an internal bypass switch to power the PA directly from the
battery. Shutdown mode turns the device off and reduces battery consumption to 0.1µA (typ.).
The LM3203 is available in a 10-pin lead free micro SMD package. A high switching frequency (2MHz) allows
use of tiny surface-mount components.
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
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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 © 2005, Texas Instruments Incorporated