The LP3910 is a programmable system power management unit that is optimized for HDD-based Portable Media Players.

The LP3910 incorporates 2 low-dropout LDO voltage regulators, 2 integrated Buck DC/DC converters with Dynamic Voltage 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 maintain 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 between USB and adapter power sources is seamless. In addition, the battery charger supports power routing, which allows system usage immediately after an external power source has been detected. The LP3910 also incorporates some advanced battery management functions such as battery temperature measurement, reverse current blocking for USB, LED charger status indication, thermally regulated internal power FETs, battery voltage monitoring, over-current protection and a 10 hour safety timer.

The Buck-Boost DC/DC converter targets the power management of Hard Disk Drives and maintains a typical operating voltage of 3.3V ±5% with a battery voltage below or above this output level. The Buck-Boost output voltage can be selected to be as low as 1.8V.

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.

The various IC parameters are programmable through a 400 kHz I2C-compatible interface.

The LP3910 is available in a thermally-enhanced 6x6x0.8 mm 48-pin WQFN package and operates over an ambient temperature range of –40°C to +85°C.

• 2 Low-Dropout Regulators: LDO1 is Used for General Purpose Applications, LDO2 is Used for Low-Noise Analog Applications. Both LDOs have Programmable Output Voltages.
• Green and Red LED Charger Status Drivers
• 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
• System Power Supply Management
• 6x6x0.8mm 48-pin WQFN Package
• Voltage and Thermal Supervisory Circuits
• Continuous Battery Voltage Monitoring
• Interrupt Request Output with 8 Sources

Key Specifications

• LDO1: 150 mA, 1.2V–3.3V
• LDO2: 150 mA, 1.3V–3.3V
• BUCK1: 600 mA, 0.8V–2.0V
• BUCK2: 600 mA, 1.8V–3.3V
• BUCK-Boost: 1000 mA, 1.8V–3.3V
• 50 mΩ Battery Path Resistance
• 100 mA to 1000 mA Full-Rate Charge Current Using Wall Sdapter
• 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
• 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