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

= 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.

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

C2 G1 Gain setting input 1

C3 G0 Gain setting input 0

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

30009502

Power V

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

≤ 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|

SDIH

SDIL

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

SDL

= GND

SDR

GAIN0, GAIN1 = GND

RL = ∞

GAIN0 = VDD, GAIN1 = GND

RL = ∞

GAIN0 = GND, GAIN1 = V

RL = ∞

GAIN0, GAIN1 = V

RL = ∞

AV = 6dB

AV = 12dB

AV = 18dB

AV = 24dB

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

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

37.5

22.5

12.5

4.2

kΩ

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Symbol Parameter Conditions

LM48411

RL = 15μH + 4Ω + 15μH THD = 10% (max) f = 1kHz, 22kHz BW VDD = 5V VDD = 3.6V

Output Power

THD+N Total Harmonic Distortion + Noise

PSRR

Power Supply Rejection Ratio (Input Referred)

SNR Signal to Noise Ratio

OUT

CMRR

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

= 200mVPP Sine,

Ripple

= 217Hz, VDD = 3.6, 5V

Ripple

Inputs to AC GND, CI = 2μF

= 200mVPP Sine,

Ripple

= 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

Sine

LM48411

Typical Limit

(Note 6) (Notes 7, 8)

2.5

1.2

530

2.0

1.0

430

0.05 %

0.03

Units

(Limits)

W W

μV

RMS

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