LM4890 1 Watt Audio Power Amplifier
May 2003
LM4890
1 Watt Audio Power Amplifier
General Description
The LM4890 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 LM4890 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 LM4890 features a low-power consumption shutdown
mode, which is achieved by driving the shutdown pin with
logic low. Additionally, the LM4890 features an internal ther-
mal shutdown protection mechanism.
The LM4890 contains advanced pop & click circuitry which
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4890 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j
PSRR at 217Hz, V
DD
= 5V (Fig. 1)
j
Power Output at 5.0V & 1% THD
j
Power Output at 3.3V & 1% THD
j
Shutdown Current
62dB(typ.)
1W(typ.)
400mW(typ.)
0.1µA(typ.)
Features
n
Available in space-saving packages: micro SMD, MSOP,
SOIC, and LLP
n
Ultra low current shutdown mode
n
BTL output can drive capacitive loads
n
Improved pop & click circuitry eliminates noises 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
Thermal shutdown protection
n
Unity-gain stable
n
External gain configuration capability
Applications
n
Mobile Phones
n
PDAs
n
Portable electronic devices
Connection Diagrams
8 Bump micro SMD
8 bump micro SMD Marking
20019270
20019223
Top View
Order Number LM4890IBP, LM4890IBPX
See NS Package Number BPA08DDB
Top View
X - Date Code
T - Die Traceability
G - Boomer Family
E - LM4890IBP
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation
DS200192
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
