1FEATURES

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

The LP3921 is a fully integrated charger and multi-

regulator 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. 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). Boomer

Audio Power Amplifiers were designed specifically to

provide high quality output power with a minimal

amount of external components. The Boomer Audio

Amplifier does not require output coupling capacitors

or bootstrap capacitors, and therefore is ideally suited

for mobile phone and other low voltage applications

where minimal power consumption and part count is

the primary requirement. The Boomer Audio Amplifier

contains advanced pop & click circuitry which

eliminates noises during turn-on and turn-off

transitions.