NSC LM1896N-1, LM1896N-2 Datasheet

TL/H/7920

LM1896/LM2896 Dual Audio Power Amplifier

February 1995

LM1896/LM2896 Dual Audio Power Amplifier

General Description

The LM1896 is a high performance 6V stereo power amplifier designed to deliver 1 watt/channel into 4X or 2 watts bridged monaural into 8X. Utilizing a unique patented compensation scheme, the LM1896 is ideal for sensitive AM radio applications. This new circuit technique exhibits lower wideband noise, lower distortion, and less AM radiation than conventional designs. The amplifier’s wide supply range (3V–9V) is ideal for battery operation. For higher supplies (V

S

l

9V) the LM2896 is available in an 11-lead single-inline package. The LM2896 package has been redesigned, resulting in the slightly degraded thermal characteristics shown in the figure Device Dissipation vs Ambient Temperature.

Features

Y

Low AM radiation

Y

Low noise

Y

3V, 4X, stereo P

o

e

250 mW

Y

Wide supply operation 3V–15V (LM2896)

Y

Low distortion

Y

No turn on ‘‘pop’’

Y

Adjustable voltage gain and bandwidth

Y

Smooth waveform clipping

Y

P

o

e

9W bridged, LM2896

Applications

Y

Compact AM-FM radios

Y

Stereo tape recorders and players

Y

High power portable stereos

Typical Applications

TL/H/7920– 1

FIGURE 1. LM2896 in Bridge Configuration (A

V

e

400, BWe20 kHz)

Order Number LM1896N Order Number LM2896P

See NS Package Number N14A See NS Package Number P11A

C

1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings

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

Supply Voltage

LM1896 V

S

e

12V

LM2896 V

S

e

18V

Operating Temperature (Note 1) 0§Ctoa70§C

Storage Temperature

b

65§Ctoa150§C

Junction Temperature 150

§

C

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

Thermal Resistance

i

JC

(DIP) 30§C/W

i

JA

(DIP) 137§C/W

i

JC

(SIP) 10§C/W

i

JA

(SIP) 55§C/W

Electrical Characteristics

Unless otherwise specified, T

A

e

25§C, A

V

e

200 (46 dB). For the LM1896; V

S

e

6V and R

L

e

4X. For LM2896,

T

TAB

e

25§C, V

S

e

12V and R

L

e

8X. Test circuit shown in

Figure 2

.

Parameter Conditions

LM1896 LM2896

Units

Min Typ Max Min Typ Max

Supply Current P

o

e

0W, Dual Mode 15 25 25 40 mA

Operating Supply Voltage 3 10 3 15 V

Output Power THDe10%, fe1 kHz

LM1896N-1 V

S

e

6V, R

L

e

4X Dual Mode 0.9 1.1 W/ch

LM1896N-2 V

S

e

6V, R

L

e

8X Bridge Mode T

A

e

25§C 1.8 2.1 W

V

S

e

9V, R

L

e

8X Dual Mode ( 1.3 W/ch

LM2896P-1 V

S

e

12V, R

L

e

8X Dual Mode 2.0 2.5 W/ch

LM2896P-2 V

S

e

12V, R

L

e

8X Bridge Mode

T

TAB

e

25§C

7.2 9.0 W

V

S

e

9V, R

L

e

4X Bridge Mode 7.8 W

V

S

e

9V, R

L

e

4X Dual Mode * 2.5 W/ch

Distortion fe1 kHz

P

o

e

50 mW 0.09 0.09 %

P

o

e

0.5W 0.11 0.11 %

P

o

e

1W 0.14 %

Power Supply Rejection C

BY

e

100 mF, fe1 kHz, C

IN

e

0.1 mF

b40b

54

b40b

54 dB

Ratio (PSRR) Output Referred, V

RIPPLE

e

250 mV

Channel Separation C

BY

e

100 mF, fe1 kHz, C

IN

e

0.1 mF

b50b

64

b50b

64 dB

Output Referred

Noise Equivalent Input Noise R

S

e

0,

C

IN

e

0.1 mF, BWe20b20 kHz 1.4 1.4 mV CCIR/ARM 1.4 1.4 mV Wideband 2.0 2.0 mV

DC Output Level 2.8 3 3.2 5.6 6 6.4 V

Input Impedance 50 100 350 50 100 350 kX

Input Offset Voltage 5 5 mV

Voltage Difference LM1896N-2, LM2896P-2

10 20 10 20 mV

between Outputs

Input Bias Current 120 120 nA

Note 1: For operation at ambient temperature greater than 25§C, the LM1896/LM2896 must be derated based on a maximum 150§C junction temperature using a thermal resistance which depends upon mounting techniques.

2

Typical Performance Curves

vs Ambient Temperature

LM2896 Device Dissipation

Temperature

Dissipation vs Ambient

LM1896 Maximum Device

Gain for Stable Operation

b

3 dB Bandwidth vs Voltage

A

V

e

54 dB, BWe30 kHz

THD and Gain vs Frequency

A

V

e

54 dB, BWe5 kHz

THD and Gain vs Frequency

A

V

e

46 dB, BWe50 kHz

THD and Gain vs Frequency

A

V

e

40 dB, BWe20 kHz

THD and Gain vs Frequency

A

V

e

34 dB, BWe50 kHz

THD and Gain vs Frequency

Speaker Lead Placement

vs Field Strength for Different

AM Recovered Audio and Noise

vs Frequency

(Referred to the Output)

Power Supply Rejection Ratio

to the Output) vs Frequency

Channel Separation (Referred

Supply Voltage

Power Output vs

TL/H/7920– 2

3