July 3, 2008
LM48411
Ultra-Low EMI, Filterless, 2.5W, Stereo, Class D Audio
Power Amplifier with E2S
LM48411 Ultra-Low EMI, Filterless, 2.5W, Stereo, Class D Audio Power Amplifier with E
General Description
The LM48411 is a single supply, high efficiency, 2.5W/channel Class D audio amplifier. The LM48411 features National's
Enhanced Emissions Suppression (E2S) system, that features a unique patent-pending ultra low EMI, spread spectrum, PWM architecture, that significantly reduces RF emissions while preserving audio quality and efficiency. The E2S
system improves battery life, reduces external component
count, board area consumption, system cost, and simplifying
design.
The LM48411 is designed to meet the demands of mobile
phones and other portable communication devices. Operating on a single 5V supply, it is capable of delivering 2.5W/
channel of continuous output power to a 4Ω load with less
than 10% THD+N. Its flexible power supply requirements allow operation from 2.4V to 5.5V. The wide band spread
spectrum architecture of the LM48411 reduces EMI-radiated
emissions due to the modulator frequency.
The LM48411 features high efficiency compared to a conventional Class AB amplifier. The E2S system includes an
advanced, patent-pending edge rate control (ERC) architecture that further reduce emissions by minimizing the high
frequency component of the device output, while maintaining
high quality audio reproduction and high efficiency (η = 87%
at VDD = 3.6V, PO = 500mW). Four gain options are pin selectable through GAIN0 and GAIN1 pins.
The LM48411 features a low-power consumption shutdown
mode. Shutdown may be enabled by driving the Shutdown
pin to a logic low (GND).
Output short circuit protection prevents the device from being
damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power up/down and
during shutdown. Independent left/right shutdown control
maximizes power savings in mixed mono/stereo applications.
Key Specifications
■ Efficiency at 3.6V, 500mW into 8Ω
speaker 87% (typ)
■ Efficiency at 3.6V, 100mW into 8Ω
speaker 80% (typ)
■ Efficiency at 5V, 1W into 8Ω
speaker 88% (typ)
■ Quiescent current, 3.6V supply 4.2mA (typ)
■ Power Output at V
RL = 4Ω, THD ≤ 10%
■ Power Output at V
RL = 8Ω, THD ≤ 10%
■ Total shutdown power supply
current
■ Single supply range
DD
DD
= 5V
2.5W (typ)
= 5V
1.5W (typ)
0.01µA (typ)
2.4V to 5.5V
Features
E2S system reduces EMI preserving Audio Quality and
■
Efficiency
Output short circuit protection
■
Stereo Class D Operation
■
No output filter required for inductive loads
■
Logic selectable gain
■
Independent shutdown control
■
Minimum external components
■
"Click and pop" suppression circuitry
■
Micro-power shutdown mode
■
Available in space-saving 0.5mm pitch micro SMD
■
package
Applications
Mobile phones
■
PDAs
■
Portable electronic devices
■
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2008 National Semiconductor Corporation 300095 www.national.com
S
2
LM48411 RF Emissions
LM48411
30009586
FIGURE 1. RF Emissions — 3in cable
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Typical Application
LM48411
FIGURE 2. Typical Audio Amplifier Application Circuit
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30009501
Connection Diagrams
LM48411
16 Bump micro SMD Package
micro SMD Marking
Order Number LM48411TL
See NS Package Number TLA16ACA
Pin Descriptions
Bump Name Function
A1 OUTLB Left Channel output B
A2 SDL Left channel active low shutdown
A3 PGND Power GND
A4 OUTRB Right channel output B
B1 OUTLA Left channel output A
B2 SDR Right channel active low shutdown
B3 AGND Ground
B4 OUTRA Right channel output A
C1
C2 G1 Gain setting input 1
C3 G0 Gain setting input 0
C4
D1 INL+ Non-inverting left channel input
D2 INL- Inverting left channel input
D3 INR- Inverting right channel input
D4 INR+ Non-inverting right channel input
Top View
PV
AV
DD
DD
30009502
Power V
DD
Power supply
Top View
X — Date Code
T— Die Traceability
G — Boomer Family
J2 — LM48411TL
30009557
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LM48411
Absolute Maximum Ratings (Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (Note 1) 6.0V
Storage Temperature −65°C to +150°C
Voltage at Any Input Pin
Power Dissipation (Note 3) Internally Limited
ESD Rating, all other pins (Note 4) 2.0kV
ESD Rating (Note 5) 200V
Junction Temperature (T
VDD + 0.3V ≥ V ≥ GND - 0.3V
)
JMAX
150°C
Thermal Resistance
θJA (micro SMD)
Soldering Information
See AN-1112 "microSMD Wafers Level Chip Scale
Package."
Operating Ratings (Notes 1, 2)
Temperature Range
T
≤ TA ≤ T
MIN
Supply Voltage
Electrical Characteristics The following specifications apply for A
otherwise specified. Limits apply for TA = 25°C. VDD = 3.6V.
Symbol Parameter Conditions
|VOS|
I
DD
I
SD
V
SDIH
V
SDIL
A
V
R
IN
T
WU
Differential Output Offset Voltage
Quiescent Power Supply Current
Shutdown Current
Shutdown voltage input high For SDR, SDL 1.4 V (min)
Shutdown voltage input low For SDR, SDL 0.4 V (max)
Gain
Input Resistance
Wake Up Time
VI = 0V, AV = 2V/V,
VDD = 2.4V to 5.0V
VIN = 0V, No Load, VDD = 5.0V 5.1 7.5 mA (max)
VIN = 0V, No Load, VDD = 3.6V 4.2 6.0 mA (max)
VIN = 0V, No Load, VDD = 2.4V 3.0 4.5 mA (max)
VIN = 0V, RL = 8Ω, VDD = 5.0V
VIN = 0V, RL = 8Ω, VDD = 3.6V
VIN = 0V, RL = 8Ω, VDD = 2.4V
V
= V
SDL
= GND
SDR
GAIN0, GAIN1 = GND
RL = ∞
GAIN0 = VDD, GAIN1 = GND
RL = ∞
GAIN0 = GND, GAIN1 = V
DD
RL = ∞
GAIN0, GAIN1 = V
DD
RL = ∞
AV = 6dB
AV = 12dB
AV = 18dB
AV = 24dB
V
SDR/SDL
= 0.4V
63.6°C/W
MAX
−40°C ≤ TA ≤ 85°C
2.4V ≤ VDD ≤ 5.5V
= 6dB, RL = 15μH+8Ω, f = 1kHz, unless
V
LM48411
Typical Limit
(Note 6) (Notes 7, 8)
Units
(Limits)
5 mV
5.2 mA
4.2 mA
3.0 mA
0.01 1.0
μA (max)
6 6±0.5 dB
12 12±0.5 dB
18 18±0.5 dB
24 24±0.5 dB
56
37.5
22.5
12.5
4.2
kΩ
kΩ
kΩ
kΩ
ms
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Symbol Parameter Conditions
LM48411
RL = 15μH + 4Ω + 15μH
THD = 10% (max)
f = 1kHz, 22kHz BW
VDD = 5V
VDD = 3.6V
P
O
P
O
Output Power
Output Power
THD+N Total Harmonic Distortion + Noise
PSRR
Power Supply Rejection Ratio
(Input Referred)
SNR Signal to Noise Ratio
ε
OUT
CMRR
η
Output Noise
(Input Referred)
Common Mode Rejection Ratio
(Input Referred)
Efficiency
Xtalk Crosstalk
VDD = 2.5V
RL = 15μH + 4Ω + 15μH
THD = 1% (max)
f = 1kHz, 22kHz BW
VDD = 5V
VDD = 3.6V
VDD = 2.5V
RL = 15μH + 8Ω + 15μH
THD = 10% (max)
f = 1kHz, 22kHz BW
VDD = 5V 1.5 W
VDD = 3.6V 760 600 mW (min)
VDD = 2.5V 330 mW
RL = 15μH + 8Ω + 15μH
THD = 1% (max)
f = 1kHz, 22kHz BW
VDD = 5V 1.25
VDD = 3.6V 615 mW
VDD = 2.5V 270
PO = 500mW, f = 1kHz, RL = 8Ω
PO = 300mW, f = 1kHz, RL = 8Ω
V
= 200mVPP Sine,
Ripple
f
= 217Hz, VDD = 3.6, 5V
Ripple
Inputs to AC GND, CI = 2μF
V
= 200mVPP Sine,
Ripple
f
= 1kHz, VDD = 3.6, 5V
Ripple
Inputs to AC GND, CI = 2μF
VDD = 5V, PO = 1W
VDD = 3.6V, A Weighted
VDD = 3.6V, V
f
= 217Hz
Ripple
VDD = 5V, P
OUT
RL = 8Ω
PO = 500mW, f = kHz
Ripple
= 1W
RMS
= 1V
PP
Sine
LM48411
Typical Limit
(Note 6) (Notes 7, 8)
2.5
1.2
530
2.0
1.0
430
0.05 %
0.03
78
77
96
22
64
88
84
Units
(Limits)
W
W
mW
W
W
mW
W
mW
%
dB
dB
dB
μV
RMS
dB
%
dB
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