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 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

www.national.com 2

Typical Application

LM48411

FIGURE 2. Typical Audio Amplifier Application Circuit

3 www.national.com

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

www.national.com 4

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

5 www.national.com

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

www.national.com 6