LM4903 Datasheet, PDF (1/17 Pages) National Semiconductor (TI) – 1 Watt Audio Power Amplifier

February 2003
LM4903
1 Watt Audio Power Amplifier
General Description
The LM4903 is an audio power amplifier primarily designed
for demanding applications in mobile phones and other por-
table communication device applications. It is capable of
delivering 1 watt of continuous average power to an 8Ω BTL
load with less than 1% distortion (THD+N) from a 5V_DC
power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4903 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for mobile phone and other low voltage appli-
cations where minimal power consumption is a primary re-
quirement.
The LM4903 features a low-power consumption shutdown
mode, which is achieved by driving the shutdown pin with
logic low. Additionally, the LM4903 features an internal ther-
mal shutdown protection mechanism.
The LM4903 contains advanced pop & click circuitry which
eliminates noise which would otherwise occur during turn-on
and turn-off transitions.
The LM4903 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j Improved PSRR at 217Hz & 1KHz
j Power Output at 5.0V, 1% THD, 8Ω
j Power Output at 3.0V, 1% THD, 4Ω
j Power Output at 3.0V, 1% THD, 8Ω
j Shutdown Current
62dB
1.07W (typ)
525mW (typ)
390mW (typ)
0.1µA (typ)
Features
n Available in space-saving MSOP package
n Ultra low current shutdown mode
n BTL output can drive capacitive loads
n Improved pop & click circuitry eliminates noise during
turn-on and turn-off transitions
n 2.0 - 5.5V operation
n No output coupling capacitors, snubber networks or
bootstrap capacitors required
n Unity-gain stable
n External gain configuration capability
Applications
n Mobile Phones
n PDAs
n Portable electronic devices
Typical Application
200467D3
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation DS200467
www.national.com