LM4765
Overture
TM
Audio Power Amplifier Series Dual 30W Audio Power
Amplifier with Mute and Standby Modes
General Description
The LM4765 is a stereo audio amplifier capable of delivering
typically 30W per channel of continuous average output
power into an 8
load with less than 0.1% (THD + N).
Each amplifier has an independent smooth transition fade-in/
out mute and a power conserving standby mode which can
be controlled by external logic.
The performance of the LM4765, 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.
Key Specifications
j
THD+N at 1 kHz at 2 x 25W 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)
j
Standby current:
6.5 mA (typ)
Features
n
SPiKe Protection
n
Minimal amount of external components necessary
n
Quiet fade-in/out mute mode
n
Standby-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.
DS100927-1
FIGURE 1. Typical Audio Amplifier Application Circuit
Plastic Package
DS100927-2
Top View
Non-Isolated Package
Order Number LM4765T
See NS Package Number TA15A
August 1998
LM4765
Overture
TM
Audio
Power
Amplifier
Series
Dual
30W
Audio
Power
Amplifier
with
Mute
and
Standby
Modes
1999 National Semiconductor Corporation
DS100927
www.national.com
Absolute Maximum Ratings
(Notes 5, 4)
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)
66V
Supply Voltage |V
CC
| + |V
EE
|
(with Input)
64V
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)
2000V
Junction Temperature (Note 8)
150C
Thermal Resistance
Non-Isolated T-Package
JC
1C/W
Soldering Information
T Package (10 sec.)
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 64V
Electrical Characteristics
(Notes 4, 5)
The following specifications apply for V
CC
= +28V, V
EE
= -28V with R
L
= 8
unless otherwise specified. Limits apply for T
A
=
25C.
Symbol
Parameter
Conditions
LM4765
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)
64
V (max)
P
O
Output Power
THD + N = 0.1% (max),
(Note 3)
(Continuous Average)
f = 1 kHz
|V
CC
| = |V
EE
| = 28V, R
L
= 8
30
25
W/ch (min)
|V
CC
| = |V
EE
| = 20V, R
L
= 4
22
15
W/ch (min)
THD + N
Total Harmonic Distortion
30 W/ch, R
L
= 8
0.08
%
Plus Noise
15 W/ch, R
L
= 4
, |V
CC
| = |V
EE
| = 20V
0.1
%
20 Hz
f
20 kHz, A
V
= 26 dB
X
talk
Channel Separation
f = 1 kHz, V
O
= 10.9 Vrms
80
dB
SR
(Note 3)
Slew Rate
V
IN
= 1.414 Vrms, t
rise
= 2 ns
18
12
V/s (min)
I
total
Total Quiescent Power
Both Amplifiers V
CM
= 0V,
(Note 2)
Supply Current
V
O
= 0V, I
O
= 0 mA
Standby: Off
50
80
mA (max)
Standby: On
6.5
8
mA (max)
V
OS
(Note 2)
Input Offset Voltage
V
CM
= 0V, I
O
= 0 mA
2.0
15
mV (max)
I
B
Input Bias Current
V
CM
= 0V, I
O
= 0 mA
0.2
0.5
A (max)
I
OS
Input Offset Current
V
CM
= 0V, I
O
= 0 mA
0.002
0.2
A (max)
I
O
Output Current Limit
|V
CC
| = |V
EE
| = 10V, t
ON
= 10 ms,
3.5
2.9
Apk (min)
V
O
= 0V
V
OD
Output Dropout Voltage
|V
CC
V
O
|, V
CC
= 20V, I
O
= +100 mA
1.8
2.3
V (max)
(Note 2)
(Note 12)
|V
O
V
EE
|, V
EE
= -20V, I
O
= -100 mA
2.5
3.2
V (max)
PSRR
Power Supply Rejection Ratio
V
CC
= 30V to 10V, V
EE
= -30V,
115
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
= 35V to 10V, V
EE
= -10V to -35V,
110
80
dB (min)
(Note 2)
V
CM
= 10V to -10V, I
O
= 0 mA
A
VOL
(Note 2)
Open Loop Voltage Gain
R
L
= 2 k
,
V
O
= 30V
110
90
dB (min)
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2
Electrical Characteristics
(Notes 4, 5) (Continued)
The following specifications apply for V
CC
= +28V, V
EE
= -28V with R
L
= 8
unless otherwise specified. Limits apply for T
A
=
25C.
Symbol
Parameter
Conditions
LM4765
Units
(Limits)
Typical
Limit
(Note 9)
(Note 10)
GBWP
Gain Bandwidth Product
f
O
= 100 kHz, V
IN
= 50 mVrms
7.5
5
MHz (min)
e
IN
Input Noise
IHF -- A Weighting Filter
2.0
8
V (max)
(Note 3)
R
IN
= 600
(Input Referred)
SNR
Signal-to-Noise Ratio
P
O
= 1W, A -- Weighted,
98
dB
Measured at 1 kHz, R
S
= 25
P
O
= 25W, A -- Weighted
108
dB
Measured at 1 kHz, R
S
= 25
A
M
Mute Attenuation
Pin 6,11 at 2.5V
115
80
dB (min)
Standby
Pin
V
IL
Standby Low Input Voltage
Not in Standby Mode
0.8
V (max)
V
IH
Standby High Input Voltage
In Standby Mode
2.0
2.5
V (min)
Mute pin
V
IL
Mute Low Input Voltage
Outputs Not Muted
0.8
V (max)
V
IH
Mute High Input Voltage
Outputs Muted
2.0
2.5
V (min)
Note 1: Operation is guaranteed up to 64V, 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 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.
www.national.com
3
Test Circuit #1
(Note 2) (DC Electrical Test Circuit)
Test Circuit #2
(Note 3) (AC Electrical Test Circuit)
DS100927-3
DS100927-4
www.national.com
4
Bridged Amplifier Application Circuit
Single Supply Application Circuit
Note:
*
Optional components dependent upon specific design requirements.
DS100927-5
FIGURE 2. Bridged Amplifier Application Circuit
DS100927-6
FIGURE 3. Single Supply Amplifier Application Circuit
www.national.com
5
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