National Semiconductor LM4879 Technical data

LM4879

1.1 Watt Audio Power Amplifier

LM4879 1.1 Watt Audio Power Amplifier

October 2004

General Description

The LM4879 is an audio power amplifier primarily designed
for demanding applications in mobile phones and other por­table communication device applications. It is capable of
delivering 1.1 watt of continuous average power to an 8Ω
BTL load with less than 1% distortion (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. The LM4879 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for lower-power portable applications where
minimal space and power consumption are primary require­ments.

The LM4879 features a low-power consumption global shut­down mode, which is achieved by driving the shutdown pin
with logic low. Additionally, the LM4879 features an internal
thermal shutdown protection mechanism.

The LM4879 contains advanced pop & click circuitry which
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.

The LM4879 is unity-gain stable and can be configured by
external gain-setting resistors.

DC

Key Specifications

j

PSRR: 5V, 3V@217Hz 62dB (typ)

j

Power Output at 5V & 1% THD+N 1.1W (typ)

j

Power Output at 3V & 1% THD+N 350mW (typ)

j

Shutdown Current 0.1µA (typ)

Features

n No output coupling capacitors, snubber networks or

bootstrap capacitors required

n Unity gain stable
n Ultra low current shutdown mode
n Fast turn on: 80ms (typ), 110ms (max) with 1.0µF

capacitor

n BTL output can drive capacitive loads up to 100pF
n Advanced pop & click circuitry eliminates noises during

turn-on and turn-off transitions

n 2.2V - 5.0V operation
n Available in space-saving µSMD, LLP, and MSOP

packages

Applications

n Mobile Phones
n PDAs
n Portable electronic devices

Typical Application

20024301

FIGURE 1. Typical Audio Amplifier Application Circuit

Boomer®is a registered trademark of National Semiconductor Corporation.

© 2004 National Semiconductor Corporation DS200243 www.national.com

Connection Diagrams

LM4879

8 Bump micro SMD 8 Bump micro SMD Marking

Top View

X - Date Code

T - Die Traceability

Top View

20024382

G - Boomer Family

N- LM4879IBP

Order Number LM4879IBP, LM4879IBPX

See NS Package Number BPA08DDB

Mini Small Outline (MSOP) Package MSOP Marking

Top View

G - Boomer Family

20024384

79-LM4879MM

Top View

NC = No Connect

Order Number LM4879MM

See NS Package Number MUB10A

9 Bump micro SMD 9 Bump micro SMD Marking

20024383

20024385

Top View

20024386

Order Number LM4879IBL, LM4879IBLX

See NS package Number BLA09AAB

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Top View

20024387

X - Date Code
T - Die Traceability
G - Boomer Family

79 - LM4879IBL

Connection Diagrams (Continued)

9 Bump micro SMD 9 Bump micro SMD Marking

LM4879

Top View

X - Date Code
T - Die Traceability
G - Boomer Family

B3 - LM4879ITL

Top View

20024386

Order Number LM4879ITL, LM4879ITLX

See NS package Number TLA09AAA

Leadless Leadframe Package (LLP) LLP Marking

Top View

Top View

20024302

Order Number LM4879SD

See NS Package Number SDC08A

N - NS Logo

U - Fab Code

Z - Assembly Plant Code

XY - Date Code

TT - Die Traceability

L4879SD - LM4879SD

200243B3

200243B6

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Absolute Maximum Ratings (Note 2)

If Military/Aerospace specified devices are required,

LM4879

please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage (Note 9) 6.0V

Storage Temperature −65˚C to +150˚C

Input Voltage −0.3V to V

Power Dissipation (Note 3) Internally Limited

DD

+0.3V

θ

(BPA08DDB) 220˚C/W (Note 10)

JA

θ

(SDC08A) 64˚C/W (Note 12)

JA

θ

(TLA09AAA) 180˚C/W (Note 10)

JA

θ

(BLA09AAB) 180˚C/W (Note 10)

JA

θ

(MUB10A) 56˚C/W

JC

θ

(MUB10A) 190˚C/W

JA

Operating Ratings

ESD Susceptibility (Note 4) 2000V

ESD Susceptibility (Note 5) 200V

Junction Temperature 150˚C

Thermal Resistance

Temperature Range

T

≤ TA≤ T

MIN

MAX

Supply Voltage 2.2V ≤ V

Electrical Characteristics VDD=5V (Notes 1, 2)

The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T

−40˚C ≤ TA≤ 85˚C

≤ 5.5V

DD

= 25˚C.

A

LM4879

Symbol Parameter Conditions

Typical Limit

(Note 6) (Notes 7, 8)

I

DD

I

SD

V

OS

P

o

THD+N Total Harmonic Distortion+Noise P

PSRR Power Supply Rejection Ratio

Quiescent Power Supply Current VIN= 0V, 8Ω BTL 5 10 mA (max)

Shutdown Current V

shutdown

= GND 0.1 2.0 µA (max)

Output Offset Voltage 5 40 mV (max)

Output Power THD+N = 1% (max); f = 1kHz 1.1 0.9 W (min)

= 0.4Wrms; f = 1kHz 0.1 %

o

V

= 200mVsine p-p, CB=

ripple

1.0µF
Input terminated with 10Ω to

68 (f = 1kHz)

62 (f =

217Hz)

55 dB (min)

ground

V

SDIH

V

SDIL

T

WU

Shutdown High Input Voltage 1.4 V (min)

Shutdown Low Input Voltage 0.4 V (max)

Wake-up Time CB= 1.0µF 80 110 ms (max)

A-Weighted; Measured across 8Ω

N

OUT

Output Noise

BTL
Input terminated with 10Ω to

26 µV

ground

Electrical Characteristics VDD= 3.0V (Notes 1, 2)

The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T

LM4879

Symbol Parameter Conditions

I

DD

I

SD

V

OS

P

o

THD+N Total Harmonic Distortion+Noise P

PSRR Power Supply Rejection Ratio

Quiescent Power Supply Current VIN= 0V, 8Ω BTL 4.5 9 mA (max)

Shutdown Current V

shutdown

= GND 0.1 2.0 µA (max)

Output Offset Voltage 5 40 mV (max)

Output Power THD+N = 1% (max); f = 1kHz 350 320 mW

= 0.15Wrms; f = 1kHz 0.1 %

o

V

= 200mVsine p-p, CB=

ripple

1.0µF
Input terminated with 10Ω to
ground

V

SDIH

V

SDIL

T

WU

Shutdown High Input Voltage 1.4 V (min)

Shutdown Low Input Voltage 0.4 V (max)

Wake-up Time CB= 1.0µF 80 110 ms (max)

Typical Limit

(Note 6) (Notes 7, 8)

68 (f = 1kHz)

62 (f =

217Hz)

55 dB (min)

= 25˚C.

A

Units

(Limits)

RMS

Units

(Limits)

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Electrical Characteristics VDD= 3.0V (Notes 1, 2)

The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T
25˚C. (Continued)

LM4879

=

A

LM4879

Symbol Parameter Conditions

Typical Limit

(Note 6) (Notes 7, 8)

A-Weighted; Measured across 8Ω

N

OUT

Output Noise

BTL
Input terminated with 10Ω to

26 µV

ground

Electrical Characteristics VDD= 2.6V (Notes 1, 2)

The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T

LM4879

Symbol Parameter Conditions

I

DD

I

SD

V

OS

Quiescent Power Supply Current VIN= 0V, 8Ω BTL 3.5 mA

Shutdown Current V

shutdown

= GND 0.1 µA

Output Offset Voltage 5 mV

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

P

o

Output Power

THD+N Total Harmonic Distortion+Noise P

PSRR Power Supply Rejection Ratio

RL=8Ω 250

R

=4Ω 350

L

= 0.1Wrms; f = 1kHz 0.1 %

o

V

= 200mVsine p-p, CB=

ripple

1.0µF
Input terminated with 10Ω to
ground

Typical Limit

(Note 6) (Notes 7, 8)

55 (f = 1kHz)

55 (f =

217Hz)

= 25˚C.

A

Units

(Limits)

RMS

Units

(Limits)

mW

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

functional, but do not guarantee specific performance limits. Electrical Characteristics state DC andAC 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
allowable power dissipation is P
curves for additional information.

Note 4: Human body model, 100pF discharged through a 1.5kΩ resistor.

Note 5: Machine Model, 220pF–240pF 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: For micro SMD only, shutdown current is measured in a Normal Room Environment. Exposure to direct sunlight will increase I

Note 9: If the product is in shutdown mode, and V

If the source impedance limits the current to a max of 10ma, then the part will be protected. If the part is enabled when V
be curtailed or the part may be permanently damaged.

Note 10: All bumps have the same thermal resistance and contribute equally when used to lower thermal resistance.

Note 11: Maximum power dissipation (P

Equation 1 shown in the Application section. It may also be obtained from the power dissipation graphs.

Note 12: The stated θ

is achieved when the LLP package’s DAP is soldered to a 4in2copper heatsink plain.

JA

DMAX

=(T

)/θJAor the number given inAbsolute Maximum Ratings, whichever is lower. For the LM4879, see power derating

JMAX–TA

exceeds 6V (to a max of 8V VDD), then most of the excess current will flow through the ESD protection circuits.

DD

) in the device occurs at an output power level significantly below full output power. P

DMAX

, θJA, and the ambient temperature TA. The maximum

JMAX

by a maximum of 2µA.

SD

is above 6V, circuit performance will

DD

can be calculated using

DMAX

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External Components Description

(Figure 1)

LM4879

Components Functional Description

1. R

2. C

3. R

4. C

5. C

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

i

high pass filter with C

Input coupling capacitor which blocks the DC voltage at the amplifiers input terminals. Also creates a

i

highpass filter with R

at fC= 1/(2π RiCi).

i

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

i

for an explanation of how to determine the value of C

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

f

Supply bypass capacitor which provides power supply filtering. Refer to the Power Supply Bypassing

S

section for information concerning proper placement and selection of the supply bypass capacitor.

Bypass pin capacitor which provides half-supply filtering. Refer to the section, Proper Selection of External

B

Components, for information concerning proper placement and selection of C

.

i

.

B

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Typical Performance Characteristics

LM4879

THD+N vs Frequency

= 5V, RL=8Ω, PWR = 250mW

V

DD

THD+N vs Frequency

= 2.6V, RL=8Ω, PWR = 100mW

V

DD

THD+N vs Frequency

VDD= 3V, RL=8Ω, PWR = 150mW

20024337 20024338

THD+N vs Frequency

VDD= 2.6V, RL=4Ω, PWR = 100mW

THD+N vs Power Out

= 5V, RL=8Ω, f = 1kHz

V

DD

20024339 20024340

THD+N vs Power Out

VDD= 3V, RL=8Ω, f = 1kHz

20024341 20024342

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Typical Performance Characteristics (Continued)

LM4879

THD+N vs Power Out

V

= 2.6V, RL=8Ω, f = 1kHz

DD

Power Supply Rejection Ratio

=5V

V

DD

THD+N vs Power Out

VDD= 2.6V, RL=4Ω, f = 1kHz

20024343 20024344

Power Supply Rejection Ratio

VDD=3V

20024345 20024373

Power Supply Rejection Ratio

= 2.6V

V

DD

20024347

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Power Dissipation vs Output Power

VDD=5V

20024346