NSC LM4882MX, LM4882MM, LM4882MDC, LM4882M Datasheet

LM4882
250mW Audio Power Amplifier with Shutdown Mode

General Description

The LM4882 is a single-ended audio power amplifier ca­pable of delivering 250 mW of continuous average power
into an 8Ω load with 1%(THD + N) from a 5V power supply.

Boomer

®

audio power amplifiers were designed specifically
to provide high quality output power with a minimal amount
of external components using surface mount packaging.
Since the LM4882 does not require bootstrap capacitors or
snubber networks, it is optimally suited for low-power por­table systems.

The LM4882 features an externally controlled, low power
consumption shutdown mode which is virtually clickless and
popless, as well as an internal thermal shutdown protection
mechanism.

The unity-gain stable LM4882 can be configured by external
gain-setting resistors.

Key Specifications

n THD+Nat1kHzat250mW

continuous average output
power into 8Ω 1.0%(max)

n Output Power at 1%THD+N

at 1kHz into 4Ω 380mW (typ)

n THD+Nat1kHzat85mW

continuous average output
power into 32Ω 0.1%(typ)

n Shutdown Current 0.7 µA (typ)

Features

n MSOP surface mount packaging
n “Click and Pop” Suppression Circuitry
n Supply voltages from 2.4V–5.5V
n Operating Temperature −40˚C to 85˚C
n Unity-gain stable
n External gain configuration capability
n No bootstrap capacitors, or snubber circuits are

necessary

Applications

n Personal Computers
n Cellular Phones
n General Purpose Audio

Typical Application Connection Diagram

Boomer®is a registered trademark of National Semiconductor Corporation.

DS100030-1

*Refer to the Application Information Section for information concerning
proper selection of the input and output coupling capacitors.

FIGURE 1. Typical Audio Amplifier Application Circuit

MSOP and SOIC Package

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Top View

Order Number LM4882MM or LM4882M

See NS Package Number MUA08A or M08A

January 1998

LM4882 250mW Audio Power Amplifier with Shutdown Mode

© 1998 National Semiconductor Corporation DS100030 www.national.com

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage 6.0 V
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) 2000V

PIn 5 1500V
Junction Temperature 150˚C
Soldering Information

Small Outline Package

Vapor Phase (60 seconds) 215˚C
Infrared (15 seconds) 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

Operating Ratings

Temperature Range

T

MIN

≤ TA≤ T

MAX

−40˚C ≤ TA≤ 85˚C

Supply Voltage 2.4V ≤ V

DD

≤ 5.5V

Electrical Characteristics (Notes 1, 2)

The following specifications apply for VDD= 5V unless otherwise specified. Limits apply for TA= 25˚C.

Symbol Parameter Conditions

LM4882

Units

(Limits)

Typical

(Note 5)

Limit

(Note 6)

I

DD

Quiescent Current VIN= 0V, IO= 0A 2 4.0 mA (max)

I

SD

Shutdown Current V

pin1=VDD

0.5 5 µA (max)

V

OS

Offset Voltage VIN= 0V 5 50 mV (max)

P

O

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

R

L

=4Ω 380 mW

R

L

=8Ω 270 250 mW (min)

R

L

=32Ω 95 mW

THD+N=10%;f=1kHz

R

L

=4Ω 480 mW

R

L

=8Ω 325 mW

R

L

=32Ω 125 mW

THD + N Total Harmonic Distortion + Noise R

L

=8Ω,PO= 250 mWrms; 0.5

%

R

L

=32Ω,PO= 85 mWrms; 0.1

%

f=1kHz

PSRR Power Supply Rejection Ratio V

pin3

= 2.5V, V

ripple

= 200 mVrms,

f = 120 Hz

50 dB

Electrical Characteristics (Notes 1, 2)

The following specifications apply for VDD= 3V unless otherwise specified. Limits apply for TA= 25˚C.

Symbol Parameter Conditions

LM4882

Units

(Limits)

Typical

(Note 5)

Limit

(Note 6)

I

DD

Quiescent Current VIN= 0V, IO= 0A 1.2 mA

I

SD

Shutdown Current V

pin1=VDD

0.3 µA

V

OS

Offset Voltage VIN=0V 5 mV

P

O

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

R

L

=8Ω 80 mW

R

L

=32Ω 30 mW

THD+N=10%;f=1kHz

R

L

=8Ω 105 mW

R

L

=32Ω 40 mW

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Electrical Characteristics (Notes 1, 2) (Continued)

The following specifications apply for VDD= 3V unless otherwise specified. Limits apply for TA= 25˚C.

Symbol Parameter Conditions

LM4882

Units

(Limits)

Typical

(Note 5)

Limit

(Note 6)

THD + N Total Harmonic Distortion + Noise R

L

=8Ω,PO= 70 mWrms; 0.25

%

R

L

=32Ω,PO= 30 mWrms; 0.3

%

f=1kHz

PSRR Power Supply Rejection Ratio V

pin3

= 2.5V, V

ripple

= 200 mVrms,

f = 120 Hz

50 dB

Note 1: All voltages are measured with respect to the ground pin, unless otherwise specified.
Note 2:

Absolute MaximumRatings

indicate limitsbeyondwhichdamage to the device mayoccur.

Operating Ratings

indicate conditionsforwhichthe device is func-

tional, butdonot 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.

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

)/θJA. For the LM4882, T

JMAX

= 150˚C, and the typical junction-to-ambient thermal resistance, when board

mounted, is 210˚C/W for the MUA08A Package and 170˚C/W for the M08A Package.

Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 5: Typicals are measured at 25˚C and represent the parametric norm.
Note 6: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).

External Components Description

(Refer to

Figure 1

)

Components Functional Description

1. R

i

Inverting input resistance which sets the closed-loop gain in conjunction with Rf. This resistor also forms a
high pass filter with C

i

at fc=1/(2πRiCi).

2. C

i

Input coupling capacitor which blocks the DC voltage at the amplifier’s input terminals. Also creates a
highpass filter with R

i

at fc=1/(2πRiCi). Refer to the section, Proper Selection of External Components,

for an explanation of how to determine the values of C

i

.

3. R

f

Feedback resistance which sets closed-loop gain in conjunction with Ri.

4. C

S

Supply bypass capacitor which provides power supply filtering. Refer to the Application Information section
for proper placement and selection of the supply bypass capacitor.

5. C

B

Bypass pin capacitor which provides half-supply filtering. Refer to the section, Proper Selection of External
Components, for information concerning proper placement and selection of C

B

.

6. C

O

Output coupling capacitor which blocks the DC voltage at the amplifier’s output. Forms a high pass filter wth
R

L

at fO=1/(2πRLCO).

Typical Performance Characteristics

THD+N vs Frequency

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THD+N vs Frequency

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THD+N vs Frequency

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Typical Performance Characteristics (Continued)

THD+N vs Frequency

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THD+N vs Frequency

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THD+N vs Frequency

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THD+N vs Frequency

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THD+N vs Frequency

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THD+N vs
Output Power

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THD+N vs
Output Power

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THD+N vs
Output Power

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