LM4992 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – 420mW Stereo Cell Phone Audio Amplifier

February 2004
LM4992
420mW Stereo Cell Phone Audio Amplifier
General Description
The LM4992 is a stereo audio power amplifier primarily
designed for demanding applications in mobile phones and
other portable communication device applications. It is ca-
pable of delivering 1 watt, per channel, of continuous aver-
age 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 LM4992 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 LM4992 features independent shutdown control for
each channel and a low-power consumption shutdown
mode, which is achieved by driving both shutdown pins with
logic low. Additionally, the LM4992 features an internal ther-
mal shutdown protection mechanism.
The LM4992 contains advanced pop & click circuitry which
eliminates noise which would otherwise occur during turn-on
and turn-off transitions.
The LM4992 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j Improved PSRR at 217Hz & 1KHz
j Stereo Output Power at 5.0V,
1% THD, 8Ω
j Stereo Output Power at 3.3V,
1% THD, 8Ω
j Shutdown Current, V_dd = 3.3V
64dB (1KHz)
1.07W (typ)
420mW (typ)
0.2µA (typ)
Features
n Available in space-saving LLP 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 2.2 - 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
Connection Diagram
SDA14A
200761E6
Top View
Order Number LM4992SD
See NS Package Number SDA14A
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS200761
www.national.com