LM4836
Stereo 2W Audio Power Amplifiers
with DC Volume Control, Bass Boost, and Input Mux
General Description
The LM4836 is a monolithic integrated circuit that provides
DC volume control, and stereo bridged audio power
amplifiers 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 LM4836 incorporates a
DC volume control, stereo bridged audio power amplifiers,
selectable gain or bass boost, and an input mux making it
optimally suited for multimedia monitors, portable radios,
desktop, and portable computer applications.
The LM4836 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 LM4836LQ and
LM4836MTE will deliver 2W into 4
. The LM4836MT will deliver 1.1W into
8
. See the Application Information section for LM4836LQ and LM4836MTE
usage information.
Note 2: An LM4836LQ and LM4836MTE that have been properly mounted
to the circuit board and forced-air cooled will deliver 2.2W into 3
.
Key Specifications
n
P
O
at 1% THD+N
n
into 3
(LM4836LQ, LM4836MTE)
2.2W(typ)
n
into 4
(LM4836LQ, LM4836MTE)
2.0W(typ)
n
into 8
(LM4836)
1.1W(typ)
n
Single-ended mode - THD+N at 85mW into
32
1.0%(typ)
n
Shutdown current
0.2A(typ)
Features
n
PC98 and PC99 Compliant
n
DC Volume Control Interface
n
Input mux
n
System Beep Detect
n
Stereo switchable bridged/single-ended power amplifiers
n
Selectable internal/external gain and bass boost
configurable
n
"Click and pop" suppression circuitry
n
Thermal shutdown protection circuitry
Applications
n
Portable and Desktop Computers
n
Multimedia Monitors
n
Portable Radios, PDAs, and Portable TVs
Connection Diagram
Boomer
is a registered trademark of NationalSemiconductor Corporation.
LLP Package
DS101088-83
Top View
Order Number LM4836LQ
See NS Package Number LQA028AA for Exposed-DAP
LLP
TSSOP Package
DS101088-2
Top View
Order Number LM4836MT
See NS Package Number MTC28 for TSSOP
Order Number LM4836MTE
See NS Package Number MXA28A for Exposed-DAP
TSSOP
March 2001
LM4836
Stereo
2W
Audio
Power
Amplifiers
with
DC
V
olume
Control,
Bass
Boost,
and
Input
Mux
2001 National Semiconductor Corporation
DS101088
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.
JC
(typ) -- LQA028AA
JC
(typ) -- MTC28
20C/W
JA
(typ) -- MTC28
80C/W
JC
(typ) -- MXA28A
2C/W
JA
(typ) -- MXA28A (Note 4)
41C/W
JA
(typ) -- MXA28A (Note 3)
54C/W
JA
(typ) -- MXA28A (Note 5)
59C/W
JA
(typ) -- MXA28A (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
LM4836
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
pin 24
= V
DD
0.2
2.0
A (max)
V
IH
Headphone Sense High Input Voltage
4
V (min)
V
IL
Headphone Sense Low Input Voltage
0.8
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
LM4836
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
C
RANGE
Attenuator Range
Gain with V
pin 5
4.5V
0
0.5
dB (max)
0
-1.0
dB (min)
C
RANGE
Attenuator Range
Attenuation with V
pin 5
= 0V
-73
-70
dB (min)
A
M
Mute Attenuation
V
pin 3
= 5V, Bridged Mode
-88
-80
dB (min)
V
pin 3
= 5V, Single-Ended Mode
-80
-70
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
LM4836
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
LM4836
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2
Electrical Characteristics for Single-Ended Mode Operation
(Continued)
(Notes 7, 10)
The following specifications apply for V
DD
= 5V and T
A
= 25C unless otherwise noted.
Symbol
Parameter
Conditions
LM4836
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
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
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
LM4836
Units
(Limits)
Typical
(Note 14)
Limit
(Note 15)
V
OS
Output Offset Voltage
V
IN
= 0V
10
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)(Note 15)
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, 20 Hz
<
f
<
20 kHz,
R
L
= 8
, A
VD
= 2
0.3
%
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 LM4836MTE exposed DAP must be soldered to the circuit board and forced-air cooled.
Note 9: When driving 4
loads from a 5V supply the LM4836MTE 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
. For the LM4836MT, T
JMAX
= 150C, and the typical junction-to-ambient thermal resistance, when board
mounted, is 80C/W assuming the MTC28 package.
Note 12: Human body model, 100 pF discharged through a 1.5 k
resistor.
Note 13: Machine Model, 220 pF240 pF 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.
LM4836
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3
Typical Application
DS101088-3
FIGURE
1.
T
ypical
Application
Circuit
LM4836
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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
MTE Specific Characteristics
Note 17: These curves show the thermal dissipation ability of the LM4836MTE at different ambient temperatures given these conditions:
500LFPM + 2in
2
: The part is soldered to a 2in
2
, 1 oz. copper plane with 500 linear feet per minute of forced-air flow across it.
2in
2
on bottom: The part is soldered to a 2in
2
, 1oz. copper plane that is on the bottom side of the PC board through 21 8 mil vias.
2in
2
: The part is soldered to a 2in
2
, 1oz. copper plane.
1in
2
: The part is soldered to a 1in
2
, 1oz. copper plane.
Not Attached: The part is not soldered down and is not forced-air cooled.
LM4836MTE
THD+N vs Output Power
DS101088-70
LM4836MTE
THD+N vs Frequency
DS101088-71
LM4836MTE
THD+N vs Output Power
DS101088-72
LM4836MTE
THD+N vs Frequency
DS101088-73
LM4836MTE
Power Dissipation vs Output Power
DS101088-65
LM4836MTE (Note 17)
Power Derating Curve
DS101088-64
LM4836
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5
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