LM4849
Stereo 2W Audio Power Amplifiers
with DC Volume Control and Input Mux
General Description
The LM4849 is a monolithic integrated circuit that provides
DC volume control, and stereo bridged audio power amplifi-
ers capable of producing 2W into 4
(Note 1) with less than
1.0% THD+N, or 2.2W into 3
(Note 2) with less than 1.0%
THD+N.
Boomer
audio integrated circuits were designed specifically
to provide high quality audio while requiring a minimum
amount of external components. The LM4849 incorporates a
DC volume control, stereo bridged audio power amplifiers,
and an input mux making it optimally suited for multimedia
monitors, portable radios, desktop, and portable computer
applications.
The LM4849 features an externally controlled, low-power
consumption shutdown mode, and both a power amplifier
and headphone mute for maximum system flexibility and
performance.
Note 1: When properly mounted to the circuit board, the LM4849MH will
deliver 2W into 4
. See the Application Information section for LM4849MH
usage information.
Note 2: An LM4849MH that has been properly mounted to the circuit board
and forced-air cooled will deliver 2.2W into 3
.
Key Specifications
j
P
O
at 1% THD+N
into 3
(Note2)
2.2W (typ)
into 4
(Note1)
2.0W (typ)
into 8
1.1W (typ)
j
Single-ended mode - THD+N at 85mW
into 32
1.0% (typ)
j
Shutdown Current
0.2A (typ)
Features
n
DC Volume Control Interface
n
Input mux
n
Stereo switchable bridged/single-ended power amplifiers
n
"Click and pop" suppression circuitry
n
Thermal shutdown protection circuitry
Applications
n
Portable and Desktop Computers
n
Multimedia, LCD Monitors/TV
n
Portable Radios, PDAs, and Portable TVs
Connection Diagram
TSSOP Package
20076702
Top View
Order Number LM4849MH
See NS Package Number MXA28A for Exposed-DAP TSSOP
Boomer
is a registered trademark of NationalSemiconductor Corporation.
August 2003
LM4849
Stereo
2W
Audio
Power
Amplifiers
with
DC
V
olume
Control
and
Input
Mux
2003 National Semiconductor Corporation
DS200767
www.national.com
Absolute Maximum Ratings
(Note 10)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage
6.0V
Storage Temperature
-65C to +150C
Input Voltage
-0.3V to V
DD
+0.3V
Power Dissipation
Internally limited
ESD Susceptibility (Note 12)
2500V
ESD Susceptibility (Note 13)
250V
Junction Temperature
150C
Soldering Information
Vapor Phase (60 sec.)
215C
Infrared (15 sec.)
220C
See AN-450 "Surface Mounting and their Effects on
Product Reliability" for other methods of soldering surface
mount devices.
JA
(typ) -- MXA28A (exposed DAP) (Note 3)
41C/W
JA
(typ) -- MXA28A (exposed DAP) (Note 4)
54C/W
JA
(typ) -- MXA28A (exposed DAP) (Note 5)
59C/W
JA
(typ) -- MXA28A (exposed DAP) (Note 6)
93C/W
Operating Ratings
Temperature Range
T
MIN
T
A
T
MAX
-40C
TA 85C
Supply Voltage
2.7V
V
DD
5.5V
Electrical Characteristics for Entire IC
(Notes 7, 10) The following specifications apply for V
DD
= 5V and T
A
= 25C unless otherwise noted.
Symbol
Parameter
Conditions
LM4849
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
V
DD
Supply Voltage
2.7
V (min)
5.5
V (max)
I
DD
Quiescent Power Supply Current
V
IN
= 0V, I
O
= 0A
15
30
mA (max)
I
SD
Shutdown Current
V
shutdown
= V
DD
0.7
2.0
A (max)
V
IH
VIN High on all Logic Inputs
0.8 x VDD
V (min)
V
IL
VIN Low on all Logic Inputs
0.2 x VDD
V (max)
Electrical Characteristics for Volume Attenuators
(Notes 7, 10) The following specifications apply for V
DD
= 5V and T
A
= 25C unless otherwise noted.
Symbol
Parameter
Conditions
LM4849
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
C
RANGE
Attenuator Range
Gain with V
DCVol
= 5.0V, No Load
0.75
dB (max)
C
RANGE
Attenuator Range
Attenuation with V
DCVol
= 0V (BM &
SE)
-75
dB (min)
A
M
Mute Attenuation
V
mute
= 5V, Bridged Mode (BM)
-78
dB (min)
V
mute
= 5V, Single-Ended Mode (SE)
-78
dB (min)
Electrical Characteristics for Single-Ended Mode Operation
(Notes 7, 10) The following specifications apply for V
DD
= 5V and T
A
= 25C unless otherwise noted.
Symbol
Parameter
Conditions
LM4849
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
P
O
Output Power
THD+N = 1.0%; f = 1kHz; R
L
= 32
85
mW
THD+N = 10%; f = 1 kHz; R
L
= 32
95
mW
THD+N
Total Harmonic Distortion+Noise
V
OUT
= 1V
RMS
, f=1kHz, R
L
= 10k
,
A
VD
= 1
0.065
%
PSRR
Power Supply Rejection Ratio
C
B
= 1.0 F, f =120 Hz,
V
RIPPLE
= 200 mVrms
58
dB
SNR
Signal to Noise Ratio
P
OUT
=75 mW, R
L
= 32
, A-Wtd
Filter
102
dB
X
talk
Channel Separation
f=1kHz, C
B
= 1.0 F
65
dB
LM4849
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2
Electrical Characteristics for Bridged Mode Operation
(Notes 7, 10) The following specifications apply for V
DD
= 5V and T
A
= 25C unless otherwise noted.
Symbol
Parameter
Conditions
LM4849
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
V
OS
Output Offset Voltage
V
IN
= 0V, No Load
50
mV (max)
P
O
Output Power
THD + N = 1.0%; f=1kHz; R
L
= 3
(Note 8)
2.2
W
THD + N = 1.0%; f=1kHz; R
L
= 4
(Note 9)
2
W
THD = 1.5% (max);f = 1 kHz;
R
L
= 8
1.1
1.0
W (min)
THD+N = 10%;f = 1 kHz; R
L
= 8
1.5
W
THD+N
Total Harmonic Distortion+Noise
P
O
= 1W, f = 1kHz,
R
L
= 8
, A
VD
= 2
0.2
%
P
O
= 340 mW, R
L
= 32
1.0
%
PSRR
Power Supply Rejection Ratio
C
B
= 1.0 F, f = 120 Hz,
V
RIPPLE
= 200 mVrms; R
L
= 8
74
dB
SNR
Signal to Noise Ratio
V
DD
= 5V, P
OUT
= 1.1W, R
L
= 8
,
A-Wtd Filter
93
dB
X
talk
Channel Separation
f=1kHz, C
B
= 1.0 F
70
dB
Note 3: The
JA
given is for an MXA28A package whose exposed-DAP is soldered to an exposed 2in
2
piece of 1 ounce printed circuit board copper.
Note 4: The
JA
given is for an MXA28A package whose exposed-DAP is soldered to a 2in
2
piece of 1 ounce printed circuit board copper on a bottom side layer
through 21 8mil vias.
Note 5: The
JA
given is for an MXA28A package whose exposed-DAP is soldered to an exposed 1in
2
piece of 1 ounce printed circuit board copper.
Note 6: The
JA
given is for an MXA28A package whose exposed-DAP is not soldered to any copper.
Note 7: All voltages are measured with respect to the ground pins, unless otherwise specified. All specifications are tested using the typical application as shown
in Figure 2.
Note 8: When driving 3
loads from a 5V supply the LM4849MH exposed DAP must be soldered to the circuit board and forced-air cooled.
Note 9: When driving 4
loads from a 5V supply the LM4849MH exposed DAP must be soldered to the circuit board.
Note 10: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which
guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit
is given, however, the typical value is a good indication of device performance.
Note 11: The maximum power dissipation must be derated at elevated temperatures and is dictated by T
JMAX
,
JA
, and the ambient temperature T
A
. The maximum
allowable power dissipation is P
DMAX
= (T
JMAX
- T
A
)/
JA
.
Note 12: Human body model, 100pF discharged through a 1.5k
resistor.
Note 13: Machine Model, 220pF240pF discharged through all pins.
Note 14: Typicals are measured at 25C and represent the parametric norm.
Note 15: Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. Limits are guaranteed to National's AOQL (Average Outgoing
Quality Level).
LM4849
www.national.com
3
Typical
Application
20076703
FIGURE
1.
T
ypical
Application
Circuit
(MH
pinout
)
LM4849
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4
Truth Table for Logic Inputs
(Note 16)
Mute
Mux Control
HP Sense
Inputs Selected
Bridged Output
Single-Ended
Output
0
0
0
Left In 1, Right In 1
Vol. Adjustable
-
0
0
1
Left In 1, Right In 1
Muted
Vol. Adjustable
0
1
0
Left In 2, Right In 2
Vol. Adjustable
-
0
1
1
Left In 2, Right In 2
Muted
Vol. Adjustable
1
X
X
-
Muted
Muted
Note 16: If system beep is detected on the Beep in pin (pin 11) and beep is fed to inputs, the system beep will be passed through the bridged amplifier regardless
of the logic of the Mute, HP sense, or DC Volume Control pins.
Typical Performance Characteristics
LM4849MH
THD+N vs Output Power
LM4849MH
THD+N vs Frequency
20076770
20076771
LM4849MH
THD+N vs Output Power
LM4849MH
THD+N vs Frequency
20076772
20076773
LM4849
www.national.com
5
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