LM4879
1.1 Watt Audio Power Amplifier
General Description
The LM4879 is an audio power amplifier primarily designed
for demanding applications in mobile phones and other por-
table communication device applications. It is capable of
delivering 1.1 watt of continuous average power to an 8
BTL load with less than 1% distortion (THD+N) from a 5V
DC
power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4879 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for lower-power portable applications where
minimal space and power consumption are primary require-
ments.
The LM4879 features a low-power consumption global shut-
down mode, which is achieved by driving the shutdown pin
with logic low. Additionally, the LM4879 features an internal
thermal shutdown protection mechanism.
The LM4879 contains advanced pop & click circuitry which
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4879 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j
PSRR: 5V, 3V
@
217Hz
62dB (typ)
j
Power Output at 5V & 1% THD+N
1.1W (typ)
j
Power Output at 3V & 1% THD+N
350mW (typ)
j
Shutdown Current
0.1A (typ)
Features
n
No output coupling capacitors, snubber networks or
bootstrap capacitors required
n
Unity gain stable
n
Ultra low current shutdown mode
n
Fast turn on: 80ms (typ), 110ms (max) with 1.0F
capacitor
n
BTL output can drive capacitive loads up to 100pF
n
Advanced pop & click circuitry eliminates noises during
turn-on and turn-off transitions
n
2.2V - 5.0V operation
n
Available in space-saving SMD, LLP, and MSOP
packages
Applications
n
Mobile Phones
n
PDAs
n
Portable electronic devices
Typical Application
Boomer
is a registered trademark of National Semiconductor Corporation.
20024301
FIGURE 1. Typical Audio Amplifier Application Circuit
October 2004
LM4879
1.1
W
att
Audio
Power
Amplifier
2004 National Semiconductor Corporation
DS200243
www.national.com
Connection Diagrams
8 Bump micro SMD
8 Bump micro SMD Marking
20024382
Top View
Order Number LM4879IBP, LM4879IBPX
See NS Package Number BPA08DDB
20024383
Top View
X - Date Code
T - Die Traceability
G - Boomer Family
N- LM4879IBP
Mini Small Outline (MSOP) Package
MSOP Marking
20024384
Top View
NC = No Connect
Order Number LM4879MM
See NS Package Number MUB10A
20024385
Top View
G - Boomer Family
79-LM4879MM
9 Bump micro SMD
9 Bump micro SMD Marking
20024386
Top View
Order Number LM4879IBL, LM4879IBLX
See NS package Number BLA09AAB
20024387
Top View
X - Date Code
T - Die Traceability
G - Boomer Family
79 - LM4879IBL
LM4879
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2
Connection Diagrams
(Continued)
9 Bump micro SMD
9 Bump micro SMD Marking
20024386
Top View
Order Number LM4879ITL, LM4879ITLX
See NS package Number TLA09AAA
200243B3
Top View
X - Date Code
T - Die Traceability
G - Boomer Family
B3 - LM4879ITL
Leadless Leadframe Package (LLP)
LLP Marking
20024302
Top View
Order Number LM4879SD
See NS Package Number SDC08A
200243B6
Top View
N - NS Logo
U - Fab Code
Z - Assembly Plant Code
XY - Date Code
TT - Die Traceability
L4879SD - LM4879SD
LM4879
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3
Absolute Maximum Ratings
(Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (Note 9)
6.0V
Storage Temperature
-65C to +150C
Input Voltage
-0.3V to V
DD
+0.3V
Power Dissipation (Note 3)
Internally Limited
ESD Susceptibility (Note 4)
2000V
ESD Susceptibility (Note 5)
200V
Junction Temperature
150C
Thermal Resistance
JA
(BPA08DDB)
220C/W (Note 10)
JA
(SDC08A)
64C/W (Note 12)
JA
(TLA09AAA)
180C/W (Note 10)
JA
(BLA09AAB)
180C/W (Note 10)
JC
(MUB10A)
56C/W
JA
(MUB10A)
190C/W
Operating Ratings
Temperature Range
T
MIN
T
A
T
MAX
-40C
T
A
85C
Supply Voltage
2.2V
V
DD
5.5V
Electrical Characteristics V
DD
= 5V
(Notes 1, 2)
The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T
A
= 25C.
Symbol
Parameter
Conditions
LM4879
Units
(Limits)
Typical
Limit
(Note 6)
(Notes 7, 8)
I
DD
Quiescent Power Supply Current
V
IN
= 0V, 8
BTL
5
10
mA (max)
I
SD
Shutdown Current
V
shutdown
= GND
0.1
2.0
A (max)
V
OS
Output Offset Voltage
5
40
mV (max)
P
o
Output Power
THD+N = 1% (max); f = 1kHz
1.1
0.9
W (min)
THD+N
Total Harmonic Distortion+Noise
P
o
= 0.4Wrms; f = 1kHz
0.1
%
PSRR
Power Supply Rejection Ratio
V
ripple
= 200mVsine p-p, C
B
=
1.0F
Input terminated with 10
to
ground
68 (f = 1kHz)
62 (f =
217Hz)
55
dB (min)
V
SDIH
Shutdown High Input Voltage
1.4
V (min)
V
SDIL
Shutdown Low Input Voltage
0.4
V (max)
T
WU
Wake-up Time
C
B
= 1.0F
80
110
ms (max)
N
OUT
Output Noise
A-Weighted; Measured across 8
BTL
Input terminated with 10
to
ground
26
V
RMS
Electrical Characteristics V
DD
= 3.0V
(Notes 1, 2)
The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T
A
= 25C.
Symbol
Parameter
Conditions
LM4879
Units
(Limits)
Typical
Limit
(Note 6)
(Notes 7, 8)
I
DD
Quiescent Power Supply Current
V
IN
= 0V, 8
BTL
4.5
9
mA (max)
I
SD
Shutdown Current
V
shutdown
= GND
0.1
2.0
A (max)
V
OS
Output Offset Voltage
5
40
mV (max)
P
o
Output Power
THD+N = 1% (max); f = 1kHz
350
320
mW
THD+N
Total Harmonic Distortion+Noise
P
o
= 0.15Wrms; f = 1kHz
0.1
%
PSRR
Power Supply Rejection Ratio
V
ripple
= 200mVsine p-p, C
B
=
1.0F
Input terminated with 10
to
ground
68 (f = 1kHz)
62 (f =
217Hz)
55
dB (min)
V
SDIH
Shutdown High Input Voltage
1.4
V (min)
V
SDIL
Shutdown Low Input Voltage
0.4
V (max)
T
WU
Wake-up Time
C
B
= 1.0F
80
110
ms (max)
LM4879
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4
Electrical Characteristics V
DD
= 3.0V
(Notes 1, 2)
The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T
A
=
25C. (Continued)
Symbol
Parameter
Conditions
LM4879
Units
(Limits)
Typical
Limit
(Note 6)
(Notes 7, 8)
N
OUT
Output Noise
A-Weighted; Measured across 8
BTL
Input terminated with 10
to
ground
26
V
RMS
Electrical Characteristics V
DD
= 2.6V
(Notes 1, 2)
The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T
A
= 25C.
Symbol
Parameter
Conditions
LM4879
Units
(Limits)
Typical
Limit
(Note 6)
(Notes 7, 8)
I
DD
Quiescent Power Supply Current
V
IN
= 0V, 8
BTL
3.5
mA
I
SD
Shutdown Current
V
shutdown
= GND
0.1
A
V
OS
Output Offset Voltage
5
mV
P
o
Output Power
THD+N = 1% (max); f = 1kHz
R
L
= 8
250
mW
R
L
= 4
350
THD+N
Total Harmonic Distortion+Noise
P
o
= 0.1Wrms; f = 1kHz
0.1
%
PSRR
Power Supply Rejection Ratio
V
ripple
= 200mVsine p-p, C
B
=
1.0F
Input terminated with 10
to
ground
55 (f = 1kHz)
55 (f =
217Hz)
dB
Note 1: All voltages are measured with respect to the ground pin, unless otherwise specified.
Note 2: 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 3: 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
or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4879, see power derating
curves for additional information.
Note 4: Human body model, 100pF discharged through a 1.5k
resistor.
Note 5: Machine Model, 220pF240pF discharged through all pins.
Note 6: Typicals are measured at 25C and represent the parametric norm.
Note 7: Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 8: For micro SMD only, shutdown current is measured in a Normal Room Environment. Exposure to direct sunlight will increase I
SD
by a maximum of 2A.
Note 9: If the product is in shutdown mode, and V
DD
exceeds 6V (to a max of 8V V
DD
), then most of the excess current will flow through the ESD protection circuits.
If the source impedance limits the current to a max of 10ma, then the part will be protected. If the part is enabled when V
DD
is above 6V, circuit performance will
be curtailed or the part may be permanently damaged.
Note 10: All bumps have the same thermal resistance and contribute equally when used to lower thermal resistance.
Note 11: Maximum power dissipation (P
DMAX
) in the device occurs at an output power level significantly below full output power. P
DMAX
can be calculated using
Equation 1 shown in the Application section. It may also be obtained from the power dissipation graphs.
Note 12: The stated
JA
is achieved when the LLP package's DAP is soldered to a 4in
2
copper heatsink plain.
LM4879
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