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LM4873 Datasheet, PDF (1/19 Pages) National Semiconductor (TI) – Dual 2.1W Audio Amplifier Plus Stereo Headphone Function | |||
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April 2000
LM4873
Dual 2.1W Audio Amplifier Plus Stereo Headphone
Function
General Description
The LM4873 is a dual bridge-connected audio power ampli-
fier which, when connected to a 5V supply, will deliver 2.1W
to a 4⦠load (Note 1) or 2.4W to a 3⦠load (Note 2)with less
than 1.0% THD+N. In addition, the headphone input pin al-
lows the amplifiers to operate in single-ended mode to drive
stereo headphones. A Mux Control pin toggles between the
two stereo sets of amplifier inputs, allowing for two select-
able amplifier closed-loop responses.
Boomer audio power amplifiers were designed specifically to
provide high quality output power from a surface mount
package while requiring few external components. To sim-
plify audio system design, the LM4873 combines dual bridge
speaker amplifiers and stereo headphone amplifiers on one
chip.
The LM4873 features an externally controlled, low-power
consumption shutdown mode, a stereo headphone amplifier
mode, and thermal shutdown protection. It also utilizes cir-
cuitry to reduce âclicks and popsâ during device turn-on.
Note 1: An LM4873MTE-1 which has been properly mounted to the circuit
board will deliver 2.1W into 4â¦. The other package options for the LM4873
will deliver 1.1W into 8â¦. See the Application Information section for
LM4873MTE-1 usage information.
Note 2: An LM4873MTE-1 which has been properly mounted to the circuit
board and forced-air cooled will deliver 2.4W into 3â¦.
Key Specifications
n PO at 1% THD+N
into 3⦠(LM4873MTE-1)
into 4⦠(LM4873MTE-1)
into 4⦠(LM4873MTE)
into 8⦠(LM4873)
n Single-ended mode - THD+N
at 75mW into 32â¦
n Shutdown current
2.4W(typ)
2.1W(typ)
1.9W(typ)
1.1W(typ)
0.5%(max)
0.7µA(typ)
Features
n Input mux control and two separate inputs per channel
n Stereo headphone amplifier mode
n âClick and popâ suppression circuitry
n Thermal shutdown protection circuitry
n Exposed-DAP TSSOP and TSSOP packaging available
Applications
n Multimedia monitors
n Portable and desktop computers
n Portable audio systems
Typical Application
* Refer to the section Proper Selection of External Components, for a detailed discussion of CB size.
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2000 National Semiconductor Corporation DS100993
DS100993-31
www.national.com
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