National Semiconductor LM48411  Technical data

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 4 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
k
k
k
k
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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