LM4879_14 Datasheet, PDF (1/28 Pages) Texas Instruments – 1.1 Watt Audio Power Amplifier

LM4879, LM4879MMBD, LM4879SDBD
www.ti.com
SNAS142F – MAY 2004 – REVISED OCTOBER 2004
LM4879
1.1 Watt Audio Power Amplifier
Check for Samples: LM4879, LM4879MMBD, LM4879SDBD
FEATURES
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•23 No output coupling capacitors, snubber
networks or bootstrap capacitors required
• Unity gain stable
• Ultra low current shutdown mode
• Fast turn on: 80ms (typ), 110ms (max) with
1.0µF capacitor
• BTL output can drive capacitive loads up to
100pF
• Advanced pop and click circuitry eliminates
noises during turn-on and turn-off transitions
• 2.2V - 5.0V operation
• Available in space-saving DSBGA, WSON, and
VSSOP packages
APPLICATIONS
• Mobile Phones
• PDAs
• Portable electronic devices
KEY SPECIFICATIONS
• PSRR: 5V, 3V at 217Hz: 62dB (typ)
• Power Output at 5V, 1%THD+N: 1.1W (typ)
• Power Output at 3V, 1%THD+N: 350mW (typ)
• Shutdown Current: 0.1µA (typ)
DESCRIPTION
The LM4879 is an 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 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
LM4879 does not require output coupling capacitors
or bootstrap capacitors, and therefore is ideally suited
for lower-power portable applications where minimal
space and power consumption are primary
requirements.
The LM4879 features a low-power consumption
global shutdown mode, which is achieved by driving
the shutdown pin with logic low. Additionally, the
LM4879 features an internal thermal shutdown
protection mechanism.
The LM4879 contains advanced pop and click
circuitry which eliminates noises which would
otherwise occur during turn-on and turn-off
transitions.
The LM4879 is unity-gain stable and can be
configured by external gain-setting resistors.
TYPICAL APPLICATION
Figure 1. Typical Audio Amplifier Application Circuit
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Boomer is a trademark of Texas Instruments.
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All other trademarks are the property of their respective owners.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004, Texas Instruments Incorporated