1FEATURES

2• Output Short Circuit Protection

• Stereo Class D Operation

• No Output Filter Required

• Logic Selectable Gain

• Independent Shutdown Control

• Minimum External Components

• Click and Pop Suppression

• Micro-Power Shutdown

• Available in Space-Saving 2mm x 2mm x

0.6mm DSBGA Package

APPLICATIONS

• Mobile Phones

• PDAs

• Laptops

KEY SPECIFICATIONS

• Efficiency at 3.6V, 100mW into 8Ω 80% (typ)

• Efficiency at 3.6V, 500mW into 8Ω 85% (typ)

• Efficiency at 5V, 1W into 8Ω 85% (typ)

• Quiescent Power Supply Current at 3.6V

Supply 4mA

• Power Output at VDD = 5V, RL = 4Ω, THD ≤ 10%

2.5W (typ)

• Power Output at VDD = 5V, RL = 8Ω, THD ≤ 10%

1.5W (typ)

• Shutdown Current 0.1μA (typ)

DESCRIPTION

The LM4674A is a single supply, high efficiency,

2.5W/channel, filterless switching audio amplifier. A

low noise PWM architecture eliminates the output

filter, reducing external component count, board area

consumption, system cost, and simplifying design.

The LM4674A is designed to meet the demands of

mobile phones and other portable communication

devices. Operating from a single 5V supply, the

device is capable of delivering 2.5W/channel of

continuous output power to a 4Ω load with less than

10% THD+N. Flexible power supply requirements

allow operation from 2.4V to 5.5V.

The LM4674A features high efficiency compared to

conventional Class AB amplifiers. When driving an

8Ω speaker from a 3.6V supply, the device features

85% efficiency at PO = 500mW. Four gain options are

pin selectable through the GAIN0 and GAIN1 pins.

Output short circuit protection prevents the device

from being damaged during fault conditions. Superior

click and pop suppression eliminates audible

transients on power-up/down and during shutdown.

Independent left/right shutdown controls maximizes

power savings in mixed mono/stereo applications.