OBSOLETE
LM4867
www.ti.com
SNAS117B –MAY 2004–REVISED OCTOBER 2004
LM4867
Output-Transient-Free Dual 2.1W Audio Amplifier
Plus No Coupling Capacitor Stereo Headphone Function
Check for Samples: LM4867
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FEATURES
DESCRIPTION
The LM4867 is a dual bridge-connected audio power
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Advanced “Click and Pop” Suppression
Circuitry
amplifier which, when connected to a 5V supply, will
(1)
(2)
deliver 2.1W to a 4Ω load
or 2.4W to a 3Ω load
•
Eliminates Headphone Amplifier Output
Coupling Capacitors (Patent Pending)
with less than 1.0% THD+N (see notes below). The
LM4867 uses advanced, latest generation circuitry to
eliminate all traces of clicks and pops when the
supply voltage is first applied. The amplifier has a
headphone-amplifier-select input pin. It is used to
switch the amplifiers from bridge to single-ended
mode for driving headphones. A new circuit topology
eliminates headphone output coupling capacitors
(patent pending). A MUX control pin allows selection
between the two sets of stereo input signals. The
MUX control can also be used to select between two
different customer-specified closed-loop responses.
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Stereo Headphone Amplifier Mode
Input Mux Control and Two Separate Inputs
Per Channel
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Thermal Shutdown Protection Circuitry
WQFN, TSSOP, and HTSSOP Packaging
Available
APPLICATIONS
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Multimedia Monitors
Boomer audio power amplifiers are designed
specifically to provide high quality output power from
a surface mount package and require few external
components. To simplify audio system design, the
LM4867 combines dual bridge speaker amplifiers and
stereo headphone amplifiers in one package.
Portable and Desktop Computers
Portable Audio Systems
KEY SPECIFICATIONS
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PO at 1% THD+N
The LM4867 features an externally controlled power-
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LM4867LQ, 3Ω Load, 2.4W (Typ)
LM4867LQ, 4Ω Load, 2.1W (Typ)
LM4867MTE, 4Ω, 1.9W (Typ)
LM4867MT, 8Ω, 1.1W (Typ)
saving micropower shutdown mode,
a
stereo
headphone amplifier mode, and thermal shutdown
protection.
(1) An LM4867LQ or LM4867MTE that has been properly
mounted to a circuit board will deliver 2.1W into 4Ω. The Mux
control can also be used to select two different closed-loop
responses. LM4867MT will deliver 1.1W into 8Ω. See the
Application Information sections for further information
concerning the LM4867LQ and the LM4867MT.
(2) An LM4867LQ or LM4867MTE that has been properly
mounted to a circuit board and forced-air cooled will deliver
2.4W into 3Ω.
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Single-Ended Mode - THD+N at 75mW into
32Ω, 0.5% (Max)
Shutdown Current, 0.7µA (Typ)
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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All trademarks are the property of their respective owners.
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