1FEATURES

2• Selectable Gain of 6dB (2V/V) or 12dB (4V/V)

• No Output or PSRR Bypass Capacitors

Required

• Improved “Click and Pop” Suppression

Circuitry

• Very Fast Turn on Time: 5ms (Typ)

• Minimum External Components

• 2.6 - 5.5V Operation

• BTL Output Can Drive Capacitive Loads

• Ultra Low Current Shutdown Mode (SD Low)

APPLICATIONS

• Portable Computers

• Desktop Computers

• Multimedia Monitors

KEY SPECIFICATIONS

• Improved PSRR at 217Hz for +3V: 71 dB

• Power Output at +5V, THD+N = 1%, 8Ω: 1.0 W

(Typ)

• Power Output at +3V, THD+N = 1%, 8Ω: 390

mW (Typ)

• Total Shutdown Power Supply Current: 0.1μA

(Typ)

DESCRIPTION

The LM4906 is an audio power amplifier primarily

designed for demanding applications in mobile

phones and other portable communication device

applications. It is capable of delivering 1W of

continuous average power to an 8Ω BTL load with

less than 1% distortion (THD+N) from a +5V power

supply.

The LM4906 is the first Texas Instruments Boomer

Power Amplifier that does not require an external

PSRR bypass capacitor. The LM4906 also has an

internal selectable gain of either 6dB or 12dB. In

addition, no output coupling capacitors or bootstrap

capacitors are required which makes the LM4906

ideally suited for cell phone and other low voltage

portable applications.

The LM4906 contains advanced pop and click circuitry that eliminates noise, which would otherwise

occur during turn-on and turn-off transitions.

Boomer audio power amplifiers were designed

specifically to provide high quality output power with a

minimal amount of external components. The

LM4906 features a low -power consumption

shutdown mode (the part is enabled by pulling the SD

pin high). Additionally, the LM4906 features an

internal thermal shutdown protection mechanism.