National Semiconductor - LP3905 Power Management Unit for Low Power Handheld Applications Data Handbook Specification User Manual
Summary
The LP3905 is a highly efficient, multi-functional Power Management Unit designed specifically for low-power handheld embedded applications. This versatile IC integrates two 600mA DC/DC buck regulators and two linear regulators, providing customized power options ranging from primary processors to peripherals. Ideal for developing portable devices that require reliable voltage regulation (1.5V–3.3V) and high energy efficiency. The datasheet covers detailed specifications, application circuits, pinout descriptions, and ordering information required for electrical design engineers building robust, low-power electronic systems.
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LP ow er anagem ent nit For Low ow er andheld pplications
LP3905 Power Management Unit For Low Power Handheld Applications General Description Key Specifications LP3905 is multi-functional Power Management Unit, Buck Regulators optimized for low power handheld applications. This device
Fixed and adjustable voltage options, range 1.0V to
integrates two 600m A DC/DC buck regulators and two
150m A linear regulators. Fixed and adjustable buck output
Up to 90% Efficiency
versions are available. The LP3905 additionally features two
Auto-switching PFM-PWM mode and fixed PWM mode
enable pins for the device output control and is offered in an
2MHz PWM fixed switching frequency (Typ)
LLP package.
600m A output current ±4% output voltage accuracy over temp.
Features
Internal softstart
Two buck regulators for powering high current processor
2.2µH inductor, 10µF Input and 10µF output Caps
functions or peripheral devices
Linear Regulators
Two linear regulators for powering internal processor
functions and I/Os Output options in the range 1.5V to 3.3V One enable pin for Buck1 and Linear Regulators 13.5µVrms output voltage noise Separate enable pin for Buck2 PSRR 70d B 1k Hz Thermal and current overload protection ±3% output voltage accuracy over full line and load regulation
Small 14–Pin LLP package (4mm 4mm 0.8mm)
0m A to 150m A output current Applications Cin 1.0µF, Cout 0.47µF for 100m A O/P Cin 1.0µF, Cout 1.0µF for 150m A O/P
Baseband Processors
80m V Dropout voltage
Peripheral Processor (Video, Audio)
Fixed output voltage devices can be customized to fit
I/O Power
system requirements. Please contact National Semiconduc-
FPGA Power
tor Sales Office.
Typical Application Circuit
FIGURE 1. Typical Application Circuit Pin LLP Package
National Semiconductor Corporation DS201529 www.national.com
Page Summary Contents For National Semiconductor - LP3905 Power Management Unit for Low Power Handheld Applications Data Handbook Specification User Manual
Manual Details
| Brand | National |
|---|---|
| Pages | 15 |
| File Size | 684.17 KB |
| Published | May 29, 2026 |
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Frequently Asked Questions
What is the general application of the LP3905?
It is a multi-functional Power Management Unit optimized for low power handheld applications.
How many types of regulators are integrated into the chip?
It integrates two 600mA DC/DC buck regulators and two 3.3V * 150mA linear regulators.
What is the recommended maximum operating temperature range?
The Ambient Temperature (T) range is -40°C to +85°C.
How can I specify fixed or adjustable outputs?
You must check the Ordering Information and select the appropriate suffix (-00 for fixed, -30 for PWM Fixed, etc.).