May 1999
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 4W load and 38W into 8W with 0.1% (THD + N) from 20 Hz±20 kHz.
The performance of the LM3886, utilizing its Self Peak Instantaneous Temperature (ÊKe) (SPiKe™ ) Protection Circuitry, puts it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). SPiKe Protection means that these parts are completely safeguarded at the output against overvoltage, 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 92 dB with a typical low noise floor of 2.0 µV. 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%.
n38W cont. avg. output power into 8W at VCC = ±28V
n50W cont. avg. output power into 8W at VCC = ±35V
n135W instantaneous peak output power capability
nSignal-to-Noise Ratio ³ 92 dB
nAn input mute function
nOutput protection from a short to ground or to the supplies via internal current limiting circuitry
nOutput over-voltage protection against transients from inductive loads
nSupply under-voltage protection, not allowing internal biasing to occur when |VEE| + |VCC| £ 12V, thus eliminating turn-on and turn-off transients
n11-lead TO-220 package
Applications
nComponent stereo
nCompact stereo
nSelf-powered speakers
nSurround-sound amplifiers
nHigh-end stereo TVs
Features
n 68W cont. avg. output power into 4W at VCC = ±28V
Typical Application
DS011833-1
*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
Overture™ and SPiKe ™ Protection are trademarks of National Semiconductor Corporation.
Amplifier Power Audio 68W Performance-High Series Amplifier Power Audio Overture LM3886 w/Mute
© 1999 National Semiconductor Corporation |
DS011833 |
www.national.com |
Connection Diagram
Plastic Package (Note 12)
DS011833-2
Note 1: Preliminary: 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) for
Staggered Lead Isolated Package
www.national.com |
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Absolute Maximum Ratings (Notes 6,
5)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
Supply Voltage |V+|+|V− | |
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(No Signal) |
94V |
Supply Voltage |V+|+|V− | |
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(Input Signal) |
84V |
Common Mode Input Voltage |
(V+ or V− ) and |
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|V+| + |V− | £ 80V |
Differential Input Voltage (Note 16) |
60V |
Output Current |
Internally Limited |
Power Dissipation (Note 7) |
125W |
ESD Susceptibility (Note 8) |
3000V |
Junction Temperature (Note 9) |
150ÊC |
Soldering Information |
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T Package (10 seconds) |
260ÊC |
Storage Temperature |
−40ÊC to +150ÊC |
Thermal Resistance |
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qJC |
1ÊC/W |
qJA |
43ÊC/W |
Operating Ratings (Notes 5, 6)
Temperature Range |
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TMIN £ TA £ TMAX |
−20ÊC £ TA £ +85ÊC |
Supply Voltage |V+| + |V− | |
20V to 84V |
Electrical Characteristics (Notes 5, 6)
The following specifications apply for V+ = +28V, V− |
= −28V, I MUTE = −0.5 mA with R L = 4W unless otherwise specified. Limits |
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apply for TA = 25ÊC. |
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LM3886 |
Units |
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Symbol |
Parameter |
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Conditions |
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Typical |
Limit |
(Limits) |
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(Note 10) |
(Note 11) |
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|V+| + |V− | |
Power Supply Voltage (Note 14) |
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Vpin7 − V − ³ 9V |
18 |
20 |
V (min) |
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84 |
V (max) |
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AM |
Mute Attenuation |
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Pin 8 Open or at 0V, Mute: On |
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Current out of Pin 8 > 0.5 mA, |
115 |
80 |
dB (min) |
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Mute: Off |
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PO |
Output Power (Continuous Average) |
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THD + N = 0.1% (max) |
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(Note 4) |
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f = 1 kHz; f = 20 kHz |
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|V+| = |V− | = 28V, RL = 4W |
68 |
60 |
W (min) |
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|V+| = |V− | = 28V, RL = 8W |
38 |
30 |
W (min) |
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|V+| = |V− | = 35V, RL = 8W |
50 |
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W |
Peak PO |
Instantaneous Peak Output Power |
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135 |
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W |
THD + N |
Total Harmonic Distortion Plus Noise |
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60W, RL = 4W, |
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% |
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30W, RL = 8W, |
0.03 |
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% |
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20 Hz £ f £ 20 kHz |
0.03 |
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AV = 26 dB |
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SR |
Slew Rate (Note 13) |
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VIN = 2.0Vp-p, tRISE = 2 ns |
19 |
8 |
V/µs |
(Note 4) |
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(min) |
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I+ (Note 4) |
Total Quiescent Power Supply |
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VCM = 0V, Vo = 0V, Io = 0A |
50 |
85 |
mA (max) |
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Current |
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VOS |
Input Offset Voltage |
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VCM = 0V, Io = 0 mA |
1 |
10 |
mV (max) |
(Note 3) |
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IB |
Input Bias Current |
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VCM = 0V, Io = 0 mA |
0.2 |
1 |
µA (max) |
IOS |
Input Offset Current |
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VCM = 0V, Io = 0 mA |
0.01 |
0.2 |
µA (max) |
Io |
Output Current Limit |
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|V+| = |V− | = 20V, tON = 10 ms, VO = 0V |
11.5 |
7 |
A (min) |
Vod |
Output Dropout Voltage (Note 15) |
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|V+±VO|, V+ = 28V, Io = +100 mA |
1.6 |
2.0 |
V (max) |
(Note 3) |
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|VO±V− |, V− = −28V, I o = −100 mA |
2.5 |
3.0 |
V (max) |
PSRR |
Power Supply Rejection Ratio |
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V+ = 40V to 20V, V− = −40V, |
120 |
85 |
dB (min) |
(Note 3) |
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VCM = 0V, Io = 0 mA |
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V+ = 40V, V− = −40V to −20V, |
105 |
85 |
dB (min) |
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VCM = 0V, Io = 0 mA |
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CMRR |
Common Mode Rejection Ratio |
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V+ = 60V to 20V, V− = −20V to −60V, |
110 |
85 |
dB (min) |
(Note 3) |
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VCM = 20V to −20V, I o = 0 mA |
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AVOL |
Open Loop Voltage Gain |
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|V+| = |V− | = 28V, RL = 2 kW, DVO = 40V |
115 |
90 |
dB (min) |
(Note 3) |
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GBWP |
Gain-Bandwidth Product |
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|V+| = |V− | = 30V |
8 |
2 |
MHz |
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fO = 100 kHz, VIN = 50 mVrms |
(min) |
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Electrical Characteristics (Notes 5, 6) (Continued)
The following specifications apply for V+ = +28V, V− |
= −28V, I MUTE = −0.5 mA with R L = 4Ω unless otherwise specified. Limits |
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apply for TA = 25ÊC. |
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LM3886 |
Units |
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Symbol |
Parameter |
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Conditions |
Typical |
Limit |
(Limits) |
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(Note 10) |
(Note 11) |
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eIN |
Input Noise |
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IHF Ð A Weighting Filter |
2.0 |
10 |
µV (max) |
(Note 4) |
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RIN = 600Ω (Input Referred) |
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SNR |
Signal-to-Noise Ratio |
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PO = 1W, A-Weighted, |
92.5 |
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dB |
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Measured at 1 kHz, RS = 25Ω |
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PO = 60W, A-Weighted, |
110 |
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dB |
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Measured at 1 kHz, RS = 25Ω |
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IMD |
Intermodulation Distortion Test |
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60 Hz, 7 kHz, 4:1 (SMPTE) |
0.004 |
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% |
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60 Hz, 7 kHz, 1:1 (SMPTE) |
0.009 |
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Note 2: Operation is guaranteed up to 84V, however, distortion may be introduced from SPIKeProtection Circuitry if proper thermal considerations are not taken into account. Refer to the Thermal Considerations section for more information. (See SPIKe Protection Response)
Note 3: DC Electrical Test; refer to Test Circuit #1.
Note 4: AC Electrical Test; refer to Test Circuit #2.
Note 5: All voltages are measured with respect to the GND pin (pin 7), unless otherwise specified.
Note 6: 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 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 7: For operating at case temperatures above 25ÊC, the device must be derated based on a 150ÊC maximum junction temperature and a thermal resistance of θJC = 1.0 ÊC/W (junction to case). Refer to the Thermal Resistance figure in the Application Information section under Thermal Considerations.
Note 8: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 9: The operating junction temperature maximum is 150ÊC, however, the instantaneous Safe Operating Area temperature is 250ÊC.
Note 10: Typicals are measured at 25ÊC and represent the parametric norm.
Note 11: Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 12: The LM3886T package TA11B is a non-isolated package, setting the tab of the device and the heat sink at V− potential when the LM3886 is directly mounted to the heat sink using only thermal compound. If a mica washer is used in addition to thermal compound, θCS (case to sink) is increased, but the heat sink will be isolated from V− .
Note 13: The feedback compensation network limits the bandwidth of the closed-loop response and so the slew rate will be reduced due to the high frequency roll-off. Without feedback compensation, the slew rate is typically larger.
Note 14: V− must have at least −9V at its pin with reference to ground in order for the under-voltage protection circuitry to be disabled.
Note 15: The output dropout voltage is the supply voltage minus the clipping voltage. Refer to the Clipping Voltage vs Supply Voltage graph in the Typical Performance Characteristics section.
Note 16: The Differential Input Voltage Absolute Maximum Rating is based on supply voltages of V+ = +40V and V− = −40V.
Test Circuit #1 (DC Electrical Test Circuit)
DS011833-3
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Test Circuit #2 (AC Electrical Test Circuit)
DS011833-4
Single Supply Application Circuit
DS011833-5
*Optional 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 Application Circuit
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Equivalent Schematic (excluding active protection circuitry)
DS011833-6
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