Texas Instruments LP3921
The LP3921 is a fully integrated charger and multiregulator unit with a fully differential Boomer audio power amplifier designed for CDMA cellular phones. The LP3921 has a high-speed serial interface which allows for the integration and control of a Li-Ion battery charger, 7 low-noise low-dropout (LDO) voltage regulators and a Boomer audio amplifier. The Li-Ion charger integrates a power FET, reverse current blocking diode, sense resistor with current monitor output, and requires only a few external components.FEATURES
1●23 Charger – DC Adapter or USB Input – Thermally Regulated Charge Current – Under Voltage Lockout – 50 to 950 mA Programmable Charge Current
● 3.0V to 5.5V Input Voltage Range
● Thermal Shutdown
● I2C-Compatible Interface for Controlling Charger, LDO Outputs and Enabling Audio Output
● LDO's 7 Low-Noise LDO’s – 2 x 300 mA – 3 x 150 mA – 2 x 80 mA 2% (typ.) Output Voltage Accuracy on LDO's
● Audio – Fully Differential Amplification – Ability to Drive Capacitive Loads up to 100 pF – No Output Coupling Capacitors, Snubber Networks or Bootstrap Capacitors Required
● Space-Efficient 32-pin 5 x 5 mm WQFN Package
APPLICATIONS
● CDMA Phone Handsets● Low Power Wireless Handsets
● Handheld Information Appliances
● Personal Media Players
DESCRIPTION
Charging is thermally regulated to obtain the most efficient charging rate for a given ambient temperature. LDO regulators provide high PSRR and low noise ideally suited for supplying power to both analog and digital loads. The Boomer Audio Amplifier is capable of delivering 1.1 watts of continuous average power to an 8Ω BTL load with less than 1% distortion (THD+N).