NSC LM4864MX, LM4864MMX, LM4864MM, LM4864M, LM4864N Datasheet

LM4864

300 mW Audio Power Amplifier with Shutdown Mode

General Description

The LM4864 is a bridged audio power amplifier capable of
delivering 300 mW of continuous average power into an 8Ω
load with 1%(THD) from a 5V power supply.

Boomer

®

audio power amplifiers were designed specifically
to provide high quality output power from a low supply volt­age while requiring a minimal amount of external compo­nents. Since the LM4864 does not require output coupling
capacitors, bootstrap capacitors or snubber networks, it is
optimally suited for low-power portable applications.

The LM4864 features an externally controlled, low power
consumption shutdown mode, and thermal shutdownprotec­tion.

The closed loop response of the unity-gain stable LM4864,
can be configured by external gain-setting resistors. The de­vice is available in multiple package types to suit various ap­plications.

Key Specifications

n THD at 1 kHz at 300 mW continuous

average output power into 8Ω 1.0%(max)

n THD at 1 kHz at 300 mW continuous

average output power into 16Ω 1.0%(max)

n Shutdown current 0.7 µA (typ)

Features

n MSOP, SOP, and DIP packaging
n No output coupling capacitors, bootstrap capacitors, or

snubber circuits are necessary

n Thermal shutdown protection circuitry
n Unity-gain stable
n External gain configuration capability

Applications

n Cellular Phones
n Personal Computers
n General Purpose Audio

Typical Application Connection Diagram

Boomer®is a registered trademark of National Semiconductor Corporation.

DS012607-1

FIGURE 1. Typical Audio Amplifier Application Circuit

MSOP, SOP, and DIP Package

DS012607-2

Top View

Order Number LM4864MM,

LM4864M or LM4864N

See NS Package Number MUA08A,

M08A or N08E

September 1999

LM4864 300 mW Audio Power Amplifier with Shutdown Mode

© 1999 National Semiconductor Corporation DS012607 www.national.com

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 6.0V
Storage Temperature −65˚C to +150˚C
Input Voltage −0.3V to V

DD

+ 0.3V
Power Dissipation (Note 3) Internally limited
ESD Susceptibility (Note 4) 3500V
ESD Susceptibility (Note 5) 250V
Junction Temperature 150˚C
Soldering Information

Small Outline Package

Vapor Phase (60 sec.) 215˚C
Infrared (15 sec.) 220˚C

See AN-450 “Surface Mounting and their Effects on
Product Reliability” for other methods of soldering surface
mount devices.

Thermal Resistance

θ

JC

(MSOP) 56˚ C/W

θ

JA

(MSOP) 210˚C/W

θ

JC

(SOP) 35˚C/W

θ

JA

(SOP) 170˚C/W

θ

JC

(DIP) 37˚C/W

θ

JA

(DIP) 107˚C/W

Operating Ratings

Temperature Range

T

MIN

≤ TA≤ T

MAX

−40˚C ≤ TA≤ +85˚C

Supply Voltage 2.7V ≤ V

DD

≤ 5.5V

Electrical Characteristics(Note 1) (Note 2)

The following specifications apply for V

DD

=

5V, for all available packages, unless otherwise specified. Limits apply for T

A

=

25˚C

Symbol Parameter Conditions

LM4864

Units

(Limits)

Typical

(Note 6)

Limit

(Note 7)

I

DD

Quiescent Power Supply Current V

IN

=

0V, I

O

=

0A (Note 8) 3.6 6.0 mA (max)

I

SD

Shutdown Current V

PIN1

=

V

DD

0.7 5 µA (max)

V

OS

Output Offset Voltage V

IN

=

0V 5 50 mV (max)

P

O

Output Power THD=1%(max); f=1 kHz; R

L

=

8Ω;

LM4864MM (Note 9)

300 mW (min)

THD=1%(max); f=1 kHz; R

L

=

8Ω;

LM4864M and LM4864N

675 300 mW (min)

THD+N=1%;f=1 kHz; R

L

=

16Ω;

LM4864MM, LM4864M and LM4864N

550 mW

THD+N Total Harmonic Distortion+Noise P

O

=

300 mWrms; A

VD

=

2; R

L

=

8Ω;

20 Hz ≤ f ≤ 20 kHz

0.7

%

PSRR Power Supply Rejection Ratio V

DD

=

4.9V–5.1V 50 dB

Electrical Characteristics(Note 1) (Note 2)

The following specifications apply for V

DD

=

3V, for all available packages, unless otherwise specified. Limits apply for T

A

=

25˚C

Symbol Parameter Conditions

LM4864

Units

(Limits)

Typical

(Note 6)

Limit

(Note 7)

I

DD

Quiescent Power Supply Current V

IN

=

0V, I

O

=

0A (Note 8) 1.0 3.0 mA (max)

I

SD

Shutdown Current V

PIN1

=

V

DD

0.3 2.0 µA (max)

V

OS

Output Offset Voltage V

IN

=

0V 5 mV

P

O

Output Power THD=1%(max); f=1 kHz; R

L

=

8Ω 200 mW

THD=1%(max); f=1 kHz; R

L

=

16Ω 175 mW

THD+N Total Harmonic Distortion+Noise P

O

=

100 mWrms; A

VD

=

2; R

L

=

8Ω;

20 Hz ≤ f ≤ 20 kHz, BW

<

80 kHz

1.5

%

PSRR Power Supply Rejection Ratio V

DD

=

2.9V–3.1V 50 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 func-

tional, 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.

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Electrical Characteristics(Note 1) (Note 2) (Continued)

Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by T

JMAX

, θJA, and the ambient temperature TA. The maximum

allowable power dissipation is P

DMAX

=

(T

JMAX−TA

)/θJAor the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4864, T

JMAX

=

150˚C.
The typical junction-to-ambient thermal resistance, when board mounted, is 230˚C/W for package number MUA08A, 170˚C/W for package number M08A and is
107˚C/W for package number N08E.

Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 5: Machine Model, 220 pF–240 pF discharged through all pins.
Note 6: Typicals are measured at 25˚C and represent the parametric norm.
Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 8: The quiescent power supply current depends on the offset voltage when a practical load is connected to the amplifier.
Note 9: The MUA08BA package is thermally limited to 595 mW of power dissipation at room temperature. Refering to the Power Dissipation vs Output Power graph

in the Typical Performance Characteristics section, the power dissipation limitation for the package occurs at 300 mW of output power. This package limitation is
based on 25˚C ambient temperature and θ

JA

= 210˚C. For higher output power possibilities refer to the Power Dissipation Section.

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