LM4766
Overture
TM
Audio Power Amplifier Series Dual 40W Audio Power
Amplifier with Mute
General Description
The LM4766 is a stereo audio amplifier capable of delivering
typically 40W per channel of continuous average output
power into an 8
load with less than 0.1% (THD + N).
The performance of the LM4766, utilizing its Self Peak In-
stantaneous Temperature (Ke) (SPiKe
TM
) Protection Cir-
cuitry, places it in a class above discrete and hybrid amplifi-
ers by providing an inherently, dynamically protected Safe
Operating Area (SOA). SPiKe Protection means that these
parts are safeguarded at the output against overvoltage, un-
dervoltage, overloads, including thermal runaway and in-
stantaneous temperature peaks.
Each amplifier within the LM4766 has an independent
smooth transition fade-in/out mute that minimizes output
pops. The IC's extremely low noise floor at 2 V and its ex-
tremely low THD + N value of 0.06% at the rated power
make the LM4766 optimum for high-end stereo TVs or mini-
component systems.
Key Specifications
j
THD+N at 1 kHz at 2 x 30W continuous average
output power into 8
:
0.1% (max)
j
THD+N at 1 kHz at continuous average
output power of 2 x 30W into 8
:
0.009% (typ)
Features
n
SPiKe Protection
n
Minimal amount of external components necessary
n
Quiet fade-in/out mute mode
n
Non-Isolated 15-lead TO-220 package
Applications
n
High-end stereo TVs
n
Component stereo
n
Compact stereo
Typical Application
Note: Numbers in parentheses represent pinout for amplifier B.
*
Optional component dependent upon specific design requirements.
Connection Diagram
SPiKe
TM
Protection and Overture
TM
are trademarks of National Semiconductor Corporation.
DS100928-1
FIGURE 1. Typical Audio Amplifier Application Circuit
Plastic Package
DS100928-2
Top View
Non-Isolated Package
Order Number LM4766T
See NS Package Number TA15A
September 1998
LM4766
Overture
TM
Audio
Power
Amplifier
Series
Dual
40W
Audio
Power
Amplifier
with
Mute
1999 National Semiconductor Corporation
DS100928
www.national.com
Absolute Maximum Ratings
(Notes 4, 5)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage |V
CC
| + |V
EE
|
(No Input)
78V
Supply Voltage |V
CC
| + |V
EE
|
(with Input)
74V
Common Mode Input Voltage
(V
CC
or V
EE
) and
|V
CC
| + |V
EE
|
60V
Differential Input Voltage
60V
Output Current
Internally Limited
Power Dissipation (Note 6)
62.5W
ESD Susceptability (Note 7)
3000V
Junction Temperature (Note 8)
150C
Thermal Resistance
Non-Isolated T-Package
JC
1C/W
Soldering Information
T Package
260C
Storage Temperature
-40C to +150C
Operating Ratings
(Notes 4, 5)
Temperature Range
T
MIN
T
A
T
MAX
-20C
T
A
+85C
Supply Voltage |V
CC
| + |V
EE
| (Note 1)
20V to 60V
Electrical Characteristics
(Notes 4, 5)
The following specifications apply for V
CC
= +30V, V
EE
= -30V, I
MUTE
= -0.5 mA with R
L
= 8
unless otherwise specified.
Limits apply for T
A
= 25C.
Symbol
Parameter
Conditions
LM4766
Units
(Limits)
Typical
Limit
(Note 9)
(Note 10)
|V
CC
| +
Power Supply Voltage
GND - V
EE
9V
18
20
V (min)
|V
EE
|
(Note 11)
60
V (max)
P
O
Output Power
THD + N = 0.1% (max),
(Note 3)
(Continuous Average)
f = 1 kHz, f = 20 kHz
40
30
W/ch (min)
THD + N
Total Harmonic Distortion
30 W/ch, R
L
= 8
, 20 Hz
f
20 kHz
0.06
%
Plus Noise
A
V
= 26 dB
X
talk
Channel Separation
f = 1 kHz, V
O
= 10.9 Vrms
60
dB
SR
(Note 3)
Slew Rate
V
IN
= 1.2 Vrms, t
rise
= 2 ns
9
5
V/s (min)
I
total
Total Quiescent Power
Both Amplifiers V
CM
= 0V,
48
100
mA (max)
(Note 2)
Supply Current
V
O
= 0V, I
O
= 0 mA
V
OS
(Note 2)
Input Offset Voltage
V
CM
= 0V, I
O
= 0 mA
1
10
mV (max)
I
B
Input Bias Current
V
CM
= 0V, I
O
= 0 mA
0.2
1
A (max)
I
OS
Input Offset Current
V
CM
= 0V, I
O
= 0 mA
0.01
0.2
A (max)
I
O
Output Current Limit
|V
CC
| = |V
EE
| = 10V, t
ON
= 10 ms,
4
3
Apk (min)
V
O
= 0V
V
OD
Output Dropout Voltage
|V
CC
V
O
|, V
CC
= 20V, I
O
= +100 mA
1.5
4
V (max)
(Note 2)
(Note 12)
|V
O
V
EE
|, V
EE
= -20V, I
O
= -100 mA
2.5
4
V (max)
PSRR
Power Supply Rejection Ratio
V
CC
= 30V to 10V, V
EE
= -30V,
125
85
dB (min)
(Note 2)
V
CM
= 0V, I
O
= 0 mA
V
CC
= 30V, V
EE
= -30V to -10V
110
85
dB (min)
V
CM
= 0V, I
O
= 0 mA
CMRR
Common Mode Rejection Ratio
V
CC
= 50V to 10V, V
EE
= -10V to -50V,
110
75
dB (min)
(Note 2)
V
CM
= 20V to -20V, I
O
= 0 mA
A
VOL
(Note 2)
Open Loop Voltage Gain
R
L
= 2 k
,
V
O
= 40V
115
80
dB (min)
GBWP
Gain Bandwidth Product
f
O
= 100 kHz, V
IN
= 50 mVrms
8
2
MHz (min)
e
IN
Input Noise
IHF -- A Weighting Filter
2.0
8
V (max)
(Note 3)
R
IN
= 600
(Input Referred)
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2
Electrical Characteristics
(Notes 4, 5) (Continued)
The following specifications apply for V
CC
= +30V, V
EE
= -30V, I
MUTE
= -0.5 mA with R
L
= 8
unless otherwise specified.
Limits apply for T
A
= 25C.
Symbol
Parameter
Conditions
LM4766
Units
(Limits)
Typical
Limit
(Note 9)
(Note 10)
SNR
Signal-to-Noise Ratio
P
O
= 1W, A -- Weighted,
98
dB
Measured at 1 kHz, R
S
= 25
P
O
= 25W, A -- Weighted
112
dB
Measured at 1 kHz, R
S
= 25
A
M
Mute Attenuation
Pin 6,11 at 2.5V
115
80
dB (min)
Note 1: Operation is guaranteed up to 60V, however, distortion may be introduced from SPiKe Protection Circuitry if proper thermal considerations are not taken into
account. Refer to the Application Information section for a complete explanation.
Note 2: DC Electrical Test; Refer to Test Circuit #1.
Note 3: AC Electrical Test; Refer to Test Circuit #2.
Note 4: All voltages are measured with respect to the GND pins (5, 10), unless otherwise specified.
Note 5: 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 6: For operating at case temperatures above 25C, the device must be derated based on a 150C maximum junction temperature and a thermal resistance of
JC
= 1C/W (junction to case) for the T package. Refer to the section Determining the Correct Heat Sink in the Application Information section.
Note 7: Human body model, 100 pF discharged through a 1.5 k
resistor.
Note 8: The operating junction temperature maximum is 150C, however, the instantaneous Safe Operating Area temperature is 250C.
Note 9: Typicals are measured at 25C and represent the parametric norm.
Note 10: Limits are guarantees that all parts are tested in production to meet the stated values.
Note 11: V
EE
must have at least -9V at its pin with reference to ground in order for the under-voltage protection circuitry to be disabled. In addition, the voltage dif-
ferential between V
CC
and V
EE
must be greater than 14V.
Note 12: The output dropout voltage, V
OD
, is the supply voltage minus the clipping voltage. Refer to the Clipping Voltage vs. Supply Voltage graph in the Typical Per-
formance Characteristics section.
Test Circuit #1
(Note 2) (DC Electrical Test Circuit)
DS100928-3
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3
Test Circuit #2
(Note 3) (AC Electrical Test Circuit)
Bridged Amplifier Application Circuit
DS100928-4
DS100928-5
FIGURE 2. Bridged Amplifier Application Circuit
www.national.com
4
Single Supply Application Circuit
Note:
*
Optional components dependent upon specific design requirements.
Auxiliary Amplifier Application Circuit
DS100928-6
FIGURE 3. Single Supply Amplifier Application Circuit
DS100928-7
FIGURE 4. Special Audio Amplifier Application Circuit
www.national.com
5
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