1FEATURES

2• Fully Differential Amplification

• Available in Space-saving WQFN Package

• Ultra Low Current Shutdown Mode

• Can Drive Capacitive Loads up to 100pF

• Improved Pop & Click Circuitry Eliminates

Noises During Turn-on and Turn-off

Transitions

• 2.4 - 5.5V Operation

• No Output Coupling Capacitors, Snubber

Networks or Bootstrap Capacitors Required

APPLICATIONS

• Mobile Phones

• PDAs

• Portable Electronic Devices

KEY SPECIFICATIONS

• Improved PSRR at 217Hz 85dB(typ)

• Power Output at 5.0V @ 1% THD+N 1.1W(typ)

• Power Output at 3.3V @ 1% THD+N

400mW(typ)

• Shutdown Current 0.1μA(typ)

DESCRIPTION

The LM4923 is a fully differential audio power

amplifier primarily designed for demanding

applications in mobile phones and other portable

communication device applications. It is capable of

delivering 1.1 watt of continuous average power to an

8Ω BTL load with less than 1% distortion (THD+N) from a 5VDC power supply.

Boomer audio power amplifiers were designed

specifically to provide high quality output power with a

minimal amount of external components. The

LM4923 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 is a primary

requirement.

The LM4923 features a low-power consumption

shutdown mode. To facilitate this, Shutdown may be

enabled by logic low. Additionally, the LM4923

features an internal thermal shutdown protection

mechanism.

The LM4923 contains advanced pop & click circuitry

which eliminates noises which would otherwise occur

during turn-on and turn-off transitions.