1FEATURES

2• No Output Filter Required for Inductive Loads

• Externally Configurable Gain

• Very Fast Turn On Time: 17μs (typ)

• Minimum External Components

• Click and pop Suppression Circuitry

• Micro-Power Shutdown Mode

• Available in Space-Saving DSBGA Package

APPLICATIONS

• Mobile Phones

• PDAs

• Portable Electronic Devices

KEY SPECIFICATIONS

• Efficiency @ 3.6V, 100mW into 8Ω Speaker:

80 % (typ)

• Efficiency @ 3.6V, 400mW into 8Ω Speaker:

88 % (typ)

• Efficiency @ 5V, 1W into 8Ω Speaker: 86 %

(typ)

• Quiescent Current, 3.6V Supply: 2.8 mA (typ)

• Total Shutdown Power Supply Current: 0.01

μA (typ)

• Single Supply Range: 2.4 to 5.5 V

DESCRIPTION

The LM4671 is a single supply, high efficiency 2.5W

switching audio amplifier. A low noise, filterless PWM

architecture eliminates the output filter, reducing

external component count, board area consumption,

system cost, and simplifying design.

The LM4671 is designed to meet the demands of

mobile phones and other portable communication

devices. Operating on a single 5V supply, it is

capable of driving a 4Ω speaker load at a continuous

average output of 2.1W with less than 1% THD+N. Its

flexible power supply requirements allow operation

from 2.4V to 5.5V.

The LM4671 has high efficiency with speaker loads

compared to a typical Class AB amplifier. With a 3V

supply driving an 8Ω speaker, the IC's efficiency for a

100mW power level is 80%, reaching 88% at 400mW output power.

The LM4671 features a low-power consumption shutdown mode. Shutdown may be enabled by

driving the Shutdown pin to a logic low (GND).

The gain of the LM4671 is externally configurable

which allows independent gain control from multiple

sources by summing the signals.