ADVANCE INFORMATION
November 2006
LP3910
Power Management IC for Hard Drive Based Portable Media
Players
General Description
The LP3910 is a programmable system power management
unit that is optimized for HDD-based Portable Media Players.
Features
2 low-dropout regulators -- LDO1 is used for general
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purpose applications, LDO2 is used for low-noise analog
applications. Both LDOs have programmable output
voltages.
The LP3910 incorporates 2 low-dropout LDO voltage regula-
tors, 2 integrated Buck DC/DC converters with Dynamic Volt-
age Scaling (DVS), 1 wide load range Buck-Boost DC/DC
converter with programmable output voltage, a 4-channel 8-
bit A/D converter and a dual source Li-Ion/polymer battery
charger. The charger has the capability to charge and main-
tain a single cell battery from a regulated wall adapter or USB
power. When both USB and adapter sources are present,
then the adapter source takes precedence and switching be-
tween USB and adapter power sources is seamless. In addi-
tion, the battery charger supports power routing, which allows
system usage immediately after an external power source
has been detected. The LP3910 also incorporates some ad-
vanced battery management functions such as battery tem-
perature measurement, reverse current blocking for USB,
LED charger status indication, thermally regulated internal
power FETs, battery voltage monitoring, over-current protec-
tion and a 10 hour safety timer.
Green and Red LED charger status drivers
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4-channel 8-bit dual slope a/d converter
2 High-efficiency DVS Buck converters
Wide load range Buck-Boost DC/DC converter
400 kHz I2C compatible interface
Linear constant-current / constant-voltage charger for
single cell lithium-ion batteries
USB and Adapter charging
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System power supply management
6x6x0.8mm 48 LLP package
Voltage and thermal supervisory circuits
Continuous battery voltage monitoring
Interrupt Request output with 8 sources
The Buck-Boost DC/DC converter targets the power man-
agement of Hard Disk Drives and maintains a typical operat-
ing voltage of 3.3V ±5% with a battery voltage below or above
this output level. The Buck-Boost output voltage can be se-
lected to be as low as 1.8V.
Key Specifications
LDO1: 150 mA, 1.2V–3.3V
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LDO2: 150 mA, 1.3V–3.3V
Buck1: 600 mA, 0.8V–2.0V
The 4-channel A/D converter measures the battery voltage
and charge current, which can be used for fuel gauging. Two
undedicated channels can be used to measure other analog
parameters such as discharge current, battery temperature,
keyboard resistor scanning and more.
Buck2: 600 mA, 1.8V–3.3V
Buck-Boost: 1000 mA, 1.8V–3.3V
50 mΩ battery path resistance
100 mA–1000 mA full-rate charge current using wall
adapter
The various IC parameters are programmable through a
400 kHz I2C compatible interface.
Selectable 0.05C and 0.1C EOC current
USB current limit of 100 mA, 500 mA, and 800 mA
USB pre-qual current of 50 mA
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The LP3910 is available in
a
thermally-enhanced
6x6x0.8 mm 48 LLP package and operates over an ambient
temperature range of –40°C to +85°C.
Selectable 4.1V, 4.2V or 4.38V battery termination
voltages
0.35% battery termination accuracy
±1 LSB INL/DNL on 8-bit a/d converter
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Applications
Hard drive-based MP3 players
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Portable media players
Portable gaming devices
© 2006 National Semiconductor Corporation
202123
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