If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage |V
+
| + |V
−
| (No Signal)
Supply Voltage |V | + |V | (Input
Signal)
Common Mode Input Voltage
Differential Input Voltage
Output Current
Power Dissipation (Note 3)
ESD Susceptibility (Note 4)
Junction Temperature (Note 5)
Soldering Information
T package (10 seconds)
+
−
94V
84V
(V
+
or V
−
) and
|V
+
| + |V
−
|
≤
80V
60V
Internally Limited
125W
2500V
150˚C
260˚C
Operating Ratings
(Notes 1, 2)
Temperature Range
T
MIN
≤
T
A
≤
T
MAX
Supply Voltage |V
+
| + |V
−
|
−20˚C
≤
T
A
≤
+85˚C
20V to 84V
Note:
Operation is guaranteed up to 84V, however, distortion may be intro-
duced from the
SPiKe
Protection Circuitry when operating above 70V if
proper thermal considerations are not taken into account. Refer to the
Thermal Considerations section for more information. (See
SPiKe
Protection
Response)
Electrical Characteristics
(Notes 1, 2)
The following specifications apply for V
+
= +35V, V
−
= −35V with R
L
= 8Ω unless otherwise specified. Limits apply for T
A
=
25˚C.
LM3875
Symbol
|V
+
| + |V
−
|
**P
O
Peak P
O
THD + N
**SR
*I+
*V
OS
I
B
I
OS
I
o
*V
od
*PSRR
Parameter
Power Supply Voltage
Output Power (Continuous Average)
Instantaneous Peak Output Power
Total Harmonic Distortion Plus Noise
Slew Rate (Note 9)
Total Quiescent Power Supply
Current
Input Offset Voltage
Input Bias Current
Input Offset Current
Output Current Limit
Output Dropout Voltage
Power Supply Rejection Ratio
40W, 20 Hz
≤
f
≤
20 kHz
A
V
= 26 dB
V
IN
= 1.414 Vrms, f = 10 kHz
Square-wave, R
L
= 2 kΩ
V
CM
= 0V, V
O
= 0V, I
o
= 0 mA
V
CM
= 0V, I
o
= 0 mA
V
CM
= 0V, I
o
= 0 mA
V
CM
= 0V, I
o
= 0 mA
|V | = |V | = 10V, t
on
= 10 ms, V
O
= 0V
|V
+
−V
o−
|, V
+
= 20V, I
o
= +100 mA
|V
o
−V
−
|, V
−
= −20V, I
o
= −100 mA
V
+
= 40V to 20V, V
−
= −40V,
V
cm
= 0V, I
o
= 0 mA
V
+
= 40V, V = −40V to −20V,
V
cm
= 0V, I
o
= 0 mA
V
+
= 60V to 20V, V
−
= −20V to −60V,
V
cm
= 20V to −20V, I
o
= 0 mA
|V
+
| = |V
−
| = 40V, R
L
= 2 kΩ,
∆V
O
= 60V
|V
+
| = |V
−
| = 40V
f
O
= 100 kHz, V
IN
= 50 mVrms
IHF − A Weighting Filter
R
IN
= 600Ω (Input Referred)
+
−
Conditions
Typical
(Note 6)
Limit
(Note 7)
20
84
Units
(Limits)
V (Min)
V (Max)
W (Min)
W
%
THD + N = 0.1% (Max)
f = 1 kHz, f = 20 kHz
56
100
0.06
11
30
1
0.2
0.01
6
1.6
2.7
120
120
40
5
70
10
1
0.2
4
5
5
85
85
V/µs
(Min)
mA (Max)
mV (Max)
µA (Max)
µA (Max)
A(Min)
V (Max)
V (Max)
dB (Min)
*CMRR
*A
VOL
GBWP
**e
IN
Common Mode Rejection Ratio
Open Loop Voltage Gain
Gain-Bandwidth Product
Input Noise
120
120
8
2.0
80
90
2
8.0
dB (Min)
dB (Min)
MHz
(Min)
µV (Max)
3
www.national.com
LM3875
Electrical Characteristics
(Notes 1, 2)
+
−
(Continued)
The following specifications apply for V = +35V, V = −35V with R
L
= 8Ω unless otherwise specified. Limits apply for T
A
=
25˚C.
LM3875
Parameter
Signal-to-Noise Ratio
Conditions
P
O
= 1W, A-Weighted,
Measured at 1 kHz, R
S
=25Ω
P
O
= 40W, A-Weighted,
Measured at 1 kHz, R
S
=25Ω
P
pk
= 100W, A-Weighted,
Measured at 1 kHz, R
S
=25Ω
Typical
(Note 6)
98 dB
114 dB
122 dB
0.004
0.006
Limit
(Note 7)
Units
(Limits)
dB
dB
dB
%
Symbol
SNR
IMD
Intermodulation Distortion Test
60 Hz, 7 kHz, 4:1 (SMPTE)
60 Hz, 7 kHz, 1:1 (SMPTE)
*DC Electrical Test; refer to Test Circuit #1.
**AC Electrical Test; refer to Test Circuit #2.
Note 1:
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 2:
All voltages are measured with respect to supply GND, unless otherwise specified.
Note 3:
For operating at case temperatures above 25˚C, the device must be derated based on a 150˚C maximum junction temperature and a thermal resistance
of
θ
JC
= 1.0˚C/W (junction to case). Refer to the Thermal Resistance figure in the Application Information section under
Thermal Considerations.
Note 4:
Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 5:
The operating junction temperature maximum is 150˚C, however, the instantaneous Safe Operating Area temperature is 250˚C.
Note 6:
Typicals are measured at 25˚C and represent the parametric norm.
Note 7:
Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 8:
The LM3875T package TA11B is a non-isolated package, setting the tab of the device and the heat sink at V
−
potential when the LM3875 is directly mounted
to the heat sink using only thermal compound. If a mica washer is used in addition to thermal compound,
θ
CS
(case to sink) is increased, but the heat sink will be
isolated from V
−
.
Note 9:
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 16V/µs.
Note 10:
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.
Test Circuit #1
(DC Electrical Test Circuit)
01144903
www.national.com
4
LM3875
Test Circuit #2
(AC Electrical Test Circuit)
01144904
Single Supply Application Circuit
01144905
*Optional components dependent upon specific design requirements. Refer to the External Components Description section for a component function
description.
FIGURE 2. Typical Single Supply Audio Amplifier Application Circuit
