LM4873_02 Datasheet, PDF (1/25 Pages) National Semiconductor (TI) – Dual 2.1W Audio Amplifier Plus Stereo Headphone Function

October 2002
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 4Ω load (Note 1) or 2.4W to a 3Ω load (Note 2) with less
than 1.0% THD+N. In addition, the headphone input pin
allows the amplifiers to operate in single-ended mode when
driving stereo headphones. A MUX control pin allows selec-
tion between the two stereo sets of amplifier inputs. The
MUX control can also be used to select two different
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 “clicks and pops” during device turn-on.
Note 1: An LM4873MTE-1, LM4873MTE, or LM4873LQ that has been
properly mounted to a circuit board will deliver 2.1W into 4Ω. The other
package options for the LM4873 will deliver 1.1W into 8Ω. See the Applica-
tion Information sections for further information concerning the
LM4873MTE-1, LM4873MTE, and the LM4873LQ.
Note 2: An LM4873MTE-1, LM4873MTE, or LM4873LQ that has been prop-
erly mounted to a circuit board and forced-air cooled will deliver 2.4W into 3Ω.
Key Specifications
j P_O at 1% THD+N
LM4873LQ, 3Ω, 4Ω loads
2.4W(typ), 2.1W(typ)
LM4873MTE-1, 3Ω, 4Ω loads 2.4W(typ), 2.1W(typ)
LM4873IBL, 8Ω load
1.1W(typ)
LM4873MTE, 4Ω
1.9W(typ)
LM4873, 8Ω
1.1W(typ)
j Single-ended mode THD+N
0.5%(max)
at 75mW into 32Ω
j Shutdown current
0.7µA(typ)
j Supply voltage range
2V to 5.5V
Features
n Input mux control and two separate inputs per channel
n Stereo headphone amplifier mode
n “Click and pop” suppression circuitry
n Thermal shutdown protection circuitry
n PCB area-saving micro SMD and thin micro SMD
packages
n TSSOP and exposed-DAP TSSOP and LLP packages
Applications
n Multimedia monitors
n Portable and desktop computers
n Portable audio systems
Connection Diagrams
10099330
Top View
Order Number LM4873MTE-1
See NS Package Number MXA28A for Exposed-DAP
TSSOP
10099302
Top View
Order Number LM4873MT, LM4873MTE
See NS Package Number MTC20 for TSSOP
See NS Package Number MXA20A for Exposed-DAP
TSSOP
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2002 National Semiconductor Corporation DS100993
www.national.com