1FEATURES
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) DC-
DC
• High-Efficiency Synchronous Buck Converter
• 300mA Maximum Load Capability (PWM Mode)
• 500mA Maximum Load Capability (Bypass
mode)
• PWM, Forced and Automatic Bypass Mode
• 3 Low-Dropout and Fast Transient Response
LDOs
• 16-pin DSBGA Package
• Current Overload Protection
• Thermal Overload Protection

APPLICATIONS
• Cellular Phones
• Hand-Held Radios
• Battery Powered RF Devices

DESCRIPTION
The LM3280 is a multi-functional Power Management
Unit, optimized for low-power handheld applications
such as Cellular Phones.
The LM3280 incorporates three low-dropout LDO
voltage regulators and one step down PWM DC-DC converter with an internal Bypass FET. The step
down converter's output voltage can be set using an
analog input (VCON) for optimizing efficiency of the RF
PA at various power levels. The LDO operates a
nominal output voltage of 2.85V and maximum load current capability of 20mA for a reference voltage
required by linear RF power amplifiers. The LM3280
additionally features a separate enable pin for each
output.
The LM3280 is available in a 16-pin lead free DSBGA
package.