Datasheet LM2877P Datasheet (NSC)

LM2877 Dual 4W Audio Power Amplifier

LM2877 Dual 4W Audio Power Amplifier

February 1995

General Description

The LM2877 is a monolithic dual power amplifier designed
to deliver 4W/channel continuous into 8X loads. The
LM2877 is designed to operate with a low number of exter­nal components, and still provide flexibility for use in stereo
phonographs, tape recorders and AM-FM stereo receivers,
etc. Each power amplifier is biased from a common internal
regulator to provide high power supply rejection and output
Q point centering. The LM2877 is internally compensated
for all gains greater than 10, and comes in an 11-lead sin­gle-in-line package.

Features

Y

4W/channel

Y

b

68 dB ripple rejection, output referred

Y

b

70 dB channel separation, output referred

Connection Diagram

(Single-In-Line Package)

Y

Wide supply range, 6-24V

Y

Very low cross-over distortion

Y

Low audio band noise

Y

AC short circuit protected

Y

Internal thermal shutdown

Applications

Y

Multi-channel audio systems

Y

Stereo phonographs

Y

Tape recorders and players

Y

AM-FM radio receivers

Y

Servo amplifiers

Y

Intercom systems

Y

Automotive products

Top View

TL/H/7933– 1

Order Number LM2877P

See NS Package Number P11A

*Pin 6 must be connected to GND.

C

1995 National Semiconductor Corporation RRD-B30M75/Printed in U. S. A.

TL/H/7933

Absolute Maximum Ratings

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.

Supply Voltage 26V

Ctoa70§C

§

e

20V, T

S

g

0.7V

TAB

Input Voltage

Operating Temperature 0

Electrical Characteristics V

Storage Temperature

Junction Temperature 150§C

Lead Temperature (Soldering, 10 sec.) 260§C

Thermal Resistance

i

JC

i

JA

e

25§C, R

e

L

8X,A

e

50 (34 dB) unless otherwise specified.

V

Parameter Conditions Min Typ Max Units

Total Supply Current P

e

0W 25 50 mA

O

Operating Supply Voltage 6 24 V

Output Power/Channel fe1 kHz, THDe10%, T

e

V

20V 4.0 4.5 W

S

e

V

18V 3.6 W

S

e

V

S

e

V

S

Distortion, THD fe1 kHz, V

e

P

O

e

P

O

e

P

O

e

f

1 kHz, V

e

P

O

e

P

O

e

P

O

Output Swing R

Channel Separation C

PSRR Power Supply C

e

L

e

F

Output Referred

e

V

S

e

V

S

e

F

e

12V, R
12V, R

50 mW/Channel 0.1 %

4X 1.5 1.9 W

L

e

8X 1.0 W

L

e

20V

S

1W/Channel 0.07 1 %
2W/Channel 0.07 %

e

12V, R

S

50 mW/Channel 0.25 %
500 mW/Channel 0.20 %
1W/Channel 0.15 1 %

8X V

O

O

IN

e

e

0.5 Vrms

IN

e

4 Vrms

e

0.1 mF, fe1 kHz,

0.1 mF, fe120 Hz

50 mF, C

20V, V
7V, V

50 mF, C

e

25§C

TAB

e

4X

L

S

b

50

b
b

Rejection Ratio Output Referred

e

V

20V, V

S

e

V

7V, V

S

RIPPLE

RIPPLE

e

e

0.5 Vrms

1 Vrms

b

50

b
b

Noise Equivalent Input Noise

e

0, C

IN

e

0, C

IN

e

0, fe1 kHz, R

e

0.1 mF, BWe20 Hz–20 kHz 2.5 mV

e

0.1 mF, A

e

200 0.80 mV

V

e

8X 70 dB

L

Open Loop Gain R

R

S

Output Noise Wideband
R

S

S

Input Offset Voltage 15 mV

Input Bias Current 50 nA

Input Impedance Open Loop 4 MX

DC Output Level V

e

20V 9 10 11 V

S

Slew Rate 2.0 V/ms

Power Bandwidth 65 kHz

Current Limit 1.0 A

Note 1: For operation at ambient temperature greater than 25§C, the LM2877 must be derated based on a maximum 150§C junction temperature using a thermal
resistance which depends upon device mounting techniques.

b

65§Ctoa150§C

10§C/W
55§C/W

b

4V

p-p

70 dB
60 dB

68 dB
40 dB

2

Equivalent Schematic Diagram

TL/H/7933– 2

3

Typical Performance Characteristics

Device Dissipation vs
Ambient Temperature

Power Supply Rejection Ratio
(Referred to the Output) vs
Supply Voltage

Average Supply Current vs
Power Output

Power Supply Rejection Ratio
(Referred to the Output) vs
Frequency

Channel Separation (Referred)
to the Output) vs Frequency

Total Harmonic Distortion
vs Frequency

Power Supply Rejection Ratio
(Referred to the Output) vs
Frequency

Channel Separation (Referred)
to the Output) vs Frequency

Total Harmonic Distortion
vs Frequency

Power Dissipation vs
Power Output

Open Loop Gain vs
Frequency

4

Output Swing vs Supply
Voltage

TL/H/7933– 3

Typical Applications

Stereo Phonograph Amplifier with Bass Tone Control

Frequency Response of Bass Tone Control

TL/H/7933– 5

5

TL/H/7933– 4

Typical Applications (Continued)

Stereo Amplifier with A

e

200

V

Non-Inverting Amplifier Using Split Supply

6

TL/H/7933– 6

TL/H/7933– 7

Typical Applications (Continued)

Window Comparator Driving High, Low Lamps

V

IN

a

k

(/4 V

a

to */4 V

a

a

(/4 V

l

*/4 V

Application Hints

The LM2877 is an improved LM377 in typical audio applica­tions. In the LM2877, the internal voltage regulator for the
input stage is generated from the voltage on pin 1. Normally,
the input common-mode range is within
voltage. Nevertheless, the common-mode range can be in­creased by externally forcing the voltage on pin 1. One way
to do this is to short pin 1 to the positive supply, pin 11.

g

0.7V of this pin 1

Truth Table

High Low

TL/H/7933– 8

Off On
Off Off
On Off

The only special care required with the LM2877 is to limit
the maximum input differential voltage to

g

7V. If this differ­ential voltage is exceeded, the input characteristics may
change.

Figure 1

shows a power op amp application with A

The 100k and 10k resistors set a noise gain of 10 and are

e

V

dictated by amplifier stability. The 10k resistor is boot­strapped by the feedback so the input resistance is domi­nated by the 1 MX resistor.

1.

FIGURE 1

7

TL/H/7933– 9

Physical Dimensions inches (millimeters)

LM2877 Dual 4W Audio Power Amplifier

Order Number LM2877P

See NS Package Number P11A

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with instructions for use provided in the labeling, can effectiveness.
be reasonably expected to result in a significant injury
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