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LM3886

Overture

Audio Power Amplifier Series

High-Performance 68W Audio Power Amplifier w/Mute

General Description

The LM3886 is a high-performance audio power amplifier
capable of delivering 68W of continuous average power to a
4

load and 38W into 8

with 0.1% THD+N from

20Hz–20kHz.

The performance of the LM3886, utilizing its Self Peak In-
stantaneous Temperature (˚Ke) (

SPiKe

) protection cir-

cuitry, puts it in a class above discrete and hybrid amplifiers
by providing an inherently, dynamically protected Safe Op-
erating Area (SOA).

SPiKe

protection means that these

parts are completely safeguarded at the output against ov-
ervoltage, undervoltage, overloads, including shorts to the
supplies, thermal runaway, and instantaneous temperature
peaks.

The LM3886 maintains an excellent signal-to-noise ratio of
greater than 92dB with a typical low noise floor of 2.0µV. It
exhibits extremely low THD+N values of 0.03% at the rated
output into the rated load over the audio spectrum, and
provides excellent linearity with an IMD (SMPTE) typical
rating of 0.004%.

Features

n

68W cont. avg. output power into 4

at V

CC

=

±

28V

n

38W cont. avg. output power into 8

at V

CC

=

±

28V

n

50W cont. avg. output power into 8

at V

CC

=

±

35V

n

135W instantaneous peak output power capability

n

Signal-to-Noise Ratio

92dB

n

An input mute function

n

Output protection from a short to ground or to the
supplies via internal current limiting circuitry

n

Output over-voltage protection against transients from
inductive loads

n

Supply under-voltage protection, not allowing internal
biasing to occur when |V

EE

| + |V

CC

|

12V, thus

eliminating turn-on and turn-off transients

n

11-lead TO-220 package

n

Wide supply range 20V - 94V

Applications

n

Component stereo

n

Compact stereo

n

Self-powered speakers

n

Surround-sound amplifiers

n

High-end stereo TVs

Typical Application

Overture

and

SPiKe

Protection are trademarks of National Semiconductor Corporation.

01183301

*Optional components dependent upon specific design requirements. Refer to the External Components Description section for a component functional
description.

FIGURE 1. Typical Audio Amplifier Application Circuit

October 2003

LM3886

Overture

Audio

Power

Amplifier

Series

High-Performance

68W

Audio

Power

Amplifier

w/Mute

© 2003 National Semiconductor Corporation

DS011833

www.national.com

Summary of Contents for LM3886 Overture

Page 1: ...Features n 68W cont avg output power into 4 at VCC 28V n 38W cont avg output power into 8 at VCC 28V n 50W cont avg output power into 8 at VCC 35V n 135W instantaneous peak output power capability n...

Page 2: ...liminary call you local National Sales Rep or distributor for availability Top View Order Number LM3886T or LM3886TF See NS Package Number TA11B for Staggered Lead Non Isolated Package or TF11B Note 1...

Page 3: ...cal Note 10 Limit Note 11 V V Power Supply Voltage Note 14 Vpin7 V 9V 18 20 84 V min V max AM Mute Attenuation Pin 8 Open or at 0V Mute On Current out of Pin 8 0 5 mA Mute Off 115 80 dB min PO Note 4...

Page 4: ...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 7 For operati...

Page 5: ...Test Circuit 1 DC Electrical Test Circuit 01183303 Test Circuit 2 AC Electrical Test Circuit 01183304 LM3886 www national com 5...

Page 6: ...ional components dependent upon specific design requirements Refer to the External Components Description section for a component functional description FIGURE 2 Typical Single Supply Audio Amplifier...

Page 7: ...Equivalent Schematic excluding active protection circuitry 01183306 LM3886 www national com 7...

Page 8: ...M VEE 2 6V I8 where I8 0 5 mA Refer to the Mute Attenuation vs Mute Current curves in the Typical Performance Characteristics section 13 CM Mute capacitance set up to create a large time constant for...

Page 9: ...s Safe Area SPiKe Protection Response 01183318 01183319 Supply Current vs Supply Voltage Pulse Thermal Resistance 01183320 01183321 Pulse Thermal Resistance Supply Current vs Output Voltage 01183365 0...

Page 10: ...ower Limit Pulse Power Limit 01183323 01183324 Supply Current vs Case Temperature Input Bias Current vs Case Temperature 01183325 01183326 Clipping Voltage vs Supply Voltage Clipping Voltage vs Supply...

Page 11: ...cteristics Continued THD N vs Frequency THD N vs Frequency 01183329 01183330 THD N vs Frequency THD N vs Output Power 01183331 01183332 THD N vs Output Power THD N vs Output Power 01183333 01183334 LM...

Page 12: ...istics Continued THD N vs Output Power THD N vs Output Power 01183335 01183336 THD N vs Output Power THD N vs Output Power 01183337 01183338 THD N vs Output Power THD N vs Output Power 01183339 011833...

Page 13: ...eristics Continued THD N Distribution THD N Distribution 01183341 01183342 THD N Distribution THD N Distribution 01183343 01183344 THD N Distribution Output Power vs Load Resistance 01183345 01183346...

Page 14: ...tion vs Supply Voltage 01183309 Note The maximum heat sink thermal resistance values SA in the table above were calculated using a CS 0 2 C W due to thermal compound Power Dissipation vs Output Power...

Page 15: ...eristics Continued IMD 60 Hz 7 kHz 4 1 IMD 60 Hz 7 kHz 4 1 01183351 01183352 IMD 60 Hz 1 1 IMD 60 Hz 7 kHz 1 1 01183353 01183354 IMD 60 Hz 7 kHz 1 1 Mute Attenuation vs Mute Current 01183355 01183356...

Page 16: ...istics Continued Mute Attenuation vs Mute Current Large Signal Response 01183357 01183358 Power Supply Rejection Ratio Common Mode Rejection Ratio 01183359 01183360 Open Loop Frequency Response 011833...

Page 17: ...circumstances The heat sink should be chosen to dissipate the maximum IC power for a given supply voltage and rated load With high power pulses of longer duration than 100 ms the case temperature will...

Page 18: ...rresponding parameters as described previously If the ambient temperature that the audio amplifier is to be working under is higher than the normal 25 C then the thermal resistance for the heat sink g...

Page 19: ...eater but as with any other high current amplifier the LM3886 can be made to oscillate under certain conditions These usually involve printed cir cuit board layout or output input coupling When design...

Page 20: ...ca tion some system designers may be limited to certain maxi mum supply voltages If the designer does have a power supply limitation he should choose a practical load imped ance which would allow the...

Page 21: ...uate frequency re sponse of the output PNP device can cause a turn on delay giving crossover distortion on the negative going transition through zero crossing at the higher audio frequencies THD N Tot...

Page 22: ...hen the open loop gain can be found at any frequency This is also an excellent equation to determine the 3 dB point of a closed loop gain assuming that you know the GBWP of the device Refer to the dia...

Page 23: ...Physical Dimensions inches millimeters unless otherwise noted Order Number LM3886T NS Package Number TA11B Order Number LM3886TF NS Package Number TF11B LM3886 www national com 23...

Page 24: ...oducts and packing materials meet the provisions of the Customer Products Stewardship Specification CSP 9 111C2 and the Banned Substances and Materials of Interest Specification CSP 9 111S2 and contai...

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