LM4863
Dual 2.2W Audio Amplifier Plus Stereo Headphone
Function

General Description

The LM4863 is a dual bridge-connected audio power ampli-
fier which, when connected to a 5V supply, will deliver 2.2W
to a 4

load (Note 1) or 2.5W to a 3

load (Note 2)with less

than 1.0% THD+N. In addition, the headphone input pin al-
lows the amplifiers to operate in single-ended mode to drive
stereo headphones.

Boomer audio power amplifiers were designed specifically to
provide high quality output power from a surface mount
package while requiring few external components. To sim-
plify audio system design, the LM4863 combines dual bridge
speaker amplifiers and stereo headphone amplifiers on one
chip.

The LM4863 features an externally controlled, low-power
consumption shutdown mode, a stereo headphone amplifier
mode, and thermal shutdown protection. It also utilizes cir-
cuitry to reduce "clicks and pops" during device turn-on.

Note 1:

An LM4863MTE which has been properly mounted to the circuit

board will deliver 2.2W into 4

. The other package options for the LM4863

will deliver 1.1W into 8

. See the Application Information section for

LM4863MTE usage information.

Note 2: An LM4863MTE which has been properly mounted to the circuit
board and forced-air cooled will deliver 2.5W into 3

Key Specifications

at 1% THD+N

into 3

(LM4863MTE)

2.5W(typ)

into 4

(LM4863MTE)

2.2W(typ)

into 8

(LM4863)

1.1W(typ)

Single-ended mode - THD+N

at 75mW into 32

0.5%(max)

Shutdown current

0.7µA(typ)

Features

Stereo headphone amplifier mode

"Click and pop" suppression circuitry

Unity-gain stable

Thermal shutdown protection circuitry

Exposed-DAP TSSOP, TSSOP, SOIC and DIP
packaging available

Applications

Multimedia monitors

Portable and desktop computers

Portable televisions

Typical Application

Boomer

is a registered trademark of National Semiconductor Corporation.

DS012881-1

Refer to the section Proper Selection of External Components, for a detailed discussion of C

size.

FIGURE 1. Typical Audio Amplifier Application Circuit

October 1999

LM4863

Dual

2.2W

Audio

Amplifier

Plus

Stereo

Headphone

Function

DS012881

www.national.com

Absolute Maximum Ratings

(Note 4)

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

+0.3V

Power Dissipation (Note 10)

Internally limited

ESD Susceptibility (Note 11)

2000V

ESD Susceptibility (Note 12)

200V

Junction Temperature

150°C

Solder 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 Reliablilty" for other methods of soldering surface

mount devices.

Thermal Resistance

(typ) -- M16B

20°C/W

(typ) -- M16B

80°C/W

(typ) -- N16A

20°C/W

(typ) -- N16A

63°C/W

(typ) -- MTC20

20°C/W

(typ) -- MTC20

80°C/W

(typ) -- MXA20A

2°C/W

(typ) -- MXA20A

41°C/W (Note 7)

(typ) -- MXA20A

51°C/W (Note 5)

(typ) -- MXA20A

90°C/W (Note 6)

Operating Ratings

Temperature Range

MIN

MAX

-40°C

85°C

Supply Voltage

2.0V

5.5V

Electrical Characteristics for Entire IC

(Notes 3, 4)

The following specifications apply for V

= 5V unless otherwise noted. Limits apply for T

= 25°C.

Symbol

Parameter

Conditions

LM4863

Units

(Limits)

Typical

Limit

(Note 13)

(Note 14)

Supply Voltage

V (min)

5.5

V (max)

Quiescent Power Supply Current

= 0V, I

= 0A (Note 15) , HP-IN = 0V

11.5

mA (max)

mA (min)

= 0V, I

= 0A (Note 15) , HP-IN = 4V

5.8

Shutdown Current

PIN1

= V

0.7

µA (min)

Headphone High Input Voltage

V (min)

Headphone Low Input Voltage

0.8

V (max)

Electrical Characteristics for Bridged-Mode Operation

(Notes 3, 4)

The following specifications apply for V

= 5V unless otherwise specified. Limits apply for T

= 25°C.

Symbol

Parameter

Conditions

LM4863

Units

(Limits)

Typical

Limit

(Note

13)

(Note

14)

Output Offset Voltage

= 0V

mV (max)

Output Power (Note 9)

THD = 1%, f = 1 kHz

LM4863MTE, R

= 3

(Note 7)

2.5

LM4863MTE, R

= 4

(Note 8)

2.2

LM4863, R

= 8

1.1

1.0

W (min)

THD+N = 10%, f = 1 kHz

LM4863MTE, R

= 3

(Note 7)

3.2

LM4863MTE, R

= 4

(Note 8)

2.7

LM4863, R

= 8

1.5

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

= 32

0.34

THD+N

Total Harmonic Distortion+Noise

20 Hz

20 kHz, A

= 2

LM4863MTE, R

= 4

, P

= 2W

0.3

LM4863, R

= 8

, P

= 1W

0.3

PSRR

Power Supply Rejection Ratio

= 5V, V

RIPPLE

= 200 mV

RMS

, R

= 8

= 1.0 µF

LM4863

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Electrical Characteristics for Bridged-Mode Operation

(Notes 3, 4) (Continued)

The following specifications apply for V

= 5V unless otherwise specified. Limits apply for T

= 25°C.

Symbol

Parameter

Conditions

LM4863

Units

(Limits)

Typical

Limit

(Note

13)

(Note

14)

TALK

Channel Separation

f = 1 kHz, C

= 1.0 µF

SNR

Signal To Noise Ratio

= 5V, P

= 1.1W, R

= 8

Electrical Characteristics for Single-Ended Operation

(Notes 3, 4)

The following specifications apply for V

= 5V unless otherwise specified. Limits apply for T

= 25°C.

Symbol

Parameter

Conditions

LM4863

Units

(Limits)

Typical

Limit

(Note

13)

(Note

14)

Output Offset Voltage

= 0V

mV (max)

Output Power

THD = 0.5%, f = 1 kHz, R

= 32

mW (min)

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

= 8

340

THD+N = 10%, f = 1 kHz, R

= 8

440

THD+N

Total Harmonic Distortion+Noise

= -1, P

= 75 mW, 20 Hz

20 kHz,

= 32

0.2

PSRR

Power Supply Rejection Ratio

= 1.0 µF, V

RIPPLE

= 200 mV

RMS

f = 1 kHz

TALK

Channel Separation

f = 1 kHz, C

= 1.0 µF

SNR

Signal To Noise Ratio

= 5V, P

= 340mW, R

= 8

Note 3: All voltages are measured with respect to the ground pins, 2, 7, and 15, unless otherwise specified.

Note 4: 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 guar-
antee 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 5: The

given is for an MXA20A package whose exposed-DAP is soldered to an exposed 2in

piece of 1 ounce printed circuit board copper.

Note 6: The

given is for an MXA20A package whose exposed-DAP is not soldered to any copper.

Note 7: When driving 3

loads from a 5V supply, the LM4863MTE must be mounted to the circuit board and forced-air cooled (450 linear-feet per minute).

Note 8: When driving 4

loads from a 5V supply, the LM4863MTE must be mounted to the circuit board.

Note 9: Output power is measured at the device terminals.

Note 10: The maximum power dissipation must be derated at elevated temperatures and is dictated by T

JMAX

, and the ambient temperature T

. The maximum

allowable power dissipation is P

DMAX

= (T

JMAX

- T

. For the LM4863, T

JMAX

= 150°C. For the

s for different packages, please see the Application Informa-

tion section or the Absolute Maximum Ratings section.

Note 11: Human body model, 100 pF discharged through a 1.5 k

resistor.

Note 12: Machine model, 220 pF240 pF discharged through all pins.

Note 13: Typicals are measured at 25°C and represent the parametric norm.

Note 14: Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).

Note 15: The quiescent power supply current depends on the offset voltage when a practical load is connected to the amplifier.

Truth Table for Logic Inputs

SHUTDOWN

HP-IN

LM4863 MODE

Low

Bridged

Low

High

Single-Ended

High

Low

LM4863 Shutdown

High

LM4863 Shutdown

LM4863

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External Components Description

(

Figure 1 )

Components

Functional Description

Inverting input resistance which sets the closed-loop gain in conjunction with R

. This resistor also forms a

high pass filter with C

at f

= 1/(2

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

at f

= 1/(2

). Refer to the section, Proper Selection of External Components,

for an explanation of how to determine the value of C

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

Supply bypass capacitor which provides power supply filtering. Refer to the Power Supply Bypassing
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 Components, for information concerning proper placement and selection of C

Typical Performance Characteristics
MTE Specific Characteristics

Note 16: These curves show the thermal dissipation ability of the LM4863MTE at different ambient temperatures given these conditions:

500LFPM + JEDEC board: The part is soldered to a 1S2P 20-lead exposed-DAP TSSOP test board with 500 linear feet per minute of forced-air flow across

it. Board information - copper dimensions: 74x74mm, copper coverage: 100% (buried layer) and 12% (top/bottom layers), 16 vias under the exposed-DAP.

500LFPM + 2.5in

: The part is soldered to a 2.5in

, 1 oz. copper plane with 500 linear feet per minute of forced-air flow across it.

2.5in

: The part is soldered to a 2.5in

, 1oz. copper plane.

Not Attached: The part is not soldered down and is not forced-air cooled.

LM4863MTE
THD+N vs Output Power

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LM4863MTE
THD+N vs Frequency

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LM4863MTE
THD+N vs Output Power

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LM4863MTE
THD+N vs Frequency

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LM4863MTE
Power Dissipation vs Power Output

DS012881-90

LM4863MTE(Note 16)
Power Derating Curve

DS012881-95

LM4863

Part Number LM4863