LM386 [TI]

Low Voltage Audio Power Amplifier;


型号：	LM386
厂家：	TEXAS INSTRUMENTS
描述：	Low Voltage Audio Power Amplifier 放大器光电二极管商用集成电路
文件：	总11页 (文件大小：309K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LM386

LM386 Low Voltage Audio Power Amplifier

Literature Number: SNAS545A

August 2000

LM386

Low Voltage Audio Power Amplifier

General Description

Features

n Battery operation

n Minimum external parts

The LM386 is a power amplifier designed for use in low volt-

age consumer applications. The gain is internally set to 20 to

keep external part count low, but the addition of an external

resistor and capacitor between pins 1 and 8 will increase the

gain to any value from 20 to 200.

n Wide supply voltage range: 4V–12V or 5V–18V

n Low quiescent current drain: 4mA

n Voltage gains from 20 to 200

The inputs are ground referenced while the output automati-

cally biases to one-half the supply voltage. The quiescent

power drain is only 24 milliwatts when operating from a 6 volt

supply, making the LM386 ideal for battery operation.

n Ground referenced input

n Self-centering output quiescent voltage

n Low distortion: 0.2% (A_V= 20, V_S= 6V, R_L= 8Ω, P_O

125mW, f = 1kHz)

n Available in 8 pin MSOP package

Applications

n AM-FM radio amplifiers

n Portable tape player amplifiers

n Intercoms

n TV sound systems

n Line drivers

n Ultrasonic drivers

n Small servo drivers

n Power converters

Equivalent Schematic and Connection Diagrams

Small Outline,

Molded Mini Small Outline,

and Dual-In-Line Packages

DS006976-2

Top View

Order Number LM386M-1,

LM386MM-1, LM386N-1,

LM386N-3 or LM386N-4

See NS Package Number

M08A, MUA08A or N08E

DS006976-1

DS006976

www.national.com

Absolute Maximum Ratings (Note 2)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Dual-In-Line Package

Soldering (10 sec)

Small Outline Package

(SOIC and MSOP)

Vapor Phase (60 sec)

Infrared (15 sec)

+260˚C

+215˚C

+220˚C

Supply Voltage

(LM386N-1, -3, LM386M-1)

Supply Voltage (LM386N-4)

Package Dissipation (Note 3)

(LM386N)

15V

See AN-450 “Surface Mounting Methods and Their Effect

on Product Reliability” for other methods of soldering

surface mount devices.

22V

1.25W

0.73W

Thermal Resistance

(LM386M)

θ_JC(DIP)

37˚C/W

(LM386MM-1)

0.595W

θ_JA(DIP)

107˚C/W

35˚C/W

172˚C/W

210˚C/W

56˚C/W

Input Voltage

0.4V

θ_JC(SO Package)

θ_JA(SO Package)

θ_JA(MSOP)

θ_JC(MSOP)

Storage Temperature

Operating Temperature

Junction Temperature

Soldering Information

−65˚C to +150˚C

0˚C to +70˚C

+150˚C

Electrical Characteristics (Notes 1, 2)

T_A= 25˚C

Parameter

Operating Supply Voltage (V_S)

LM386N-1, -3, LM386M-1, LM386MM-1

LM386N-4

Conditions

Min

Typ

Max

Units

Quiescent Current (I_Q)

Output Power (P_OUT

V_S= 6V, V_IN= 0

)

LM386N-1, LM386M-1, LM386MM-1

LM386N-3

V_S= 6V, R_L= 8Ω, THD = 10%

V_S= 9V, R_L= 8Ω, THD = 10%

V_S= 16V, R_L= 32Ω, THD = 10%

V_S= 6V, f = 1 kHz

250

500

700

325

700

1000

LM386N-4

Voltage Gain (A_V)

10 µF from Pin 1 to 8

Bandwidth (BW)

V_S= 6V, Pins 1 and 8 Open

V_S= 6V, R_L= 8Ω, P_OUT= 125 mW

f = 1 kHz, Pins 1 and 8 Open

V_S= 6V, f = 1 kHz, C_BYPASS= 10 µF

Pins 1 and 8 Open, Referred to Output

300

0.2

kHz

Total Harmonic Distortion (THD)

Power Supply Rejection Ratio (PSRR)

Input Resistance (R_IN

)

kΩ

Input Bias Current (I_BIAS

)

V_S= 6V, Pins 2 and 3 Open

250

Note 1: All voltages are measured with respect to the ground pin, unless otherwise specified.

Note 2: 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 3: For operation in ambient temperatures above 25˚C, the device must be derated based on a 150˚C maximum junction temperature and 1) a thermal resis-

tance of 107˚C/W junction to ambient for the dual-in-line package and 2) a thermal resistance of 170˚C/W for the small outline package.

www.national.com

Application Hints

GAIN CONTROL

INPUT BIASING

To make the LM386 a more versatile amplifier, two pins (1

and 8) are provided for gain control. With pins 1 and 8 open

the 1.35 kΩ resistor sets the gain at 20 (26 dB). If a capacitor

is put from pin 1 to 8, bypassing the 1.35 kΩ resistor, the

gain will go up to 200 (46 dB). If a resistor is placed in series

with the capacitor, the gain can be set to any value from 20

to 200. Gain control can also be done by capacitively cou-

pling a resistor (or FET) from pin 1 to ground.

The schematic shows that both inputs are biased to ground

with a 50 kΩ resistor. The base current of the input transis-

tors is about 250 nA, so the inputs are at about 12.5 mV

when left open. If the dc source resistance driving the LM386

is higher than 250 kΩ it will contribute very little additional

offset (about 2.5 mV at the input, 50 mV at the output). If the

dc source resistance is less than 10 kΩ, then shorting the

unused input to ground will keep the offset low (about 2.5 mV

at the input, 50 mV at the output). For dc source resistances

between these values we can eliminate excess offset by put-

ting a resistor from the unused input to ground, equal in

value to the dc source resistance. Of course all offset prob-

lems are eliminated if the input is capacitively coupled.

Additional external components can be placed in parallel

with the internal feedback resistors to tailor the gain and fre-

quency response for individual applications. For example,

we can compensate poor speaker bass response by fre-

quency shaping the feedback path. This is done with a series

RC from pin 1 to 5 (paralleling the internal 15 kΩ resistor).

For 6 dB effective bass boost: R . 15 kΩ, the lowest value

for good stable operation is R = 10 kΩ if pin 8 is open. If pins

1 and 8 are bypassed then R as low as 2 kΩ can be used.

This restriction is because the amplifier is only compensated

for closed-loop gains greater than 9.

When using the LM386 with higher gains (bypassing the

1.35 kΩ resistor between pins 1 and 8) it is necessary to by-

pass the unused input, preventing degradation of gain and

possible instabilities. This is done with a 0.1 µF capacitor or

a short to ground depending on the dc source resistance on

the driven input.

www.national.com

Typical Performance Characteristics

Quiescent Supply Current

vs Supply Voltage

Power Supply Rejection Ratio

(Referred to the Output)

vs Frequency

Peak-to-Peak Output Voltage

Swing vs Supply Voltage

DS006976-5

DS006976-13

DS006976-12

Voltage Gain vs Frequency

Distortion vs Frequency

Distortion vs Output Power

DS006976-15

DS006976-16

DS006976-14

Device Dissipation vs Output

Power—4Ω Load

Device Dissipation vs Output

Power—8Ω Load

Device Dissipation vs Output

Power—16Ω Load

DS006976-17

DS006976-18

DS006976-19

www.national.com

Typical Applications

Amplifier with Gain = 20

Amplifier with Gain = 200

Minimum Parts

DS006976-4

DS006976-3

Amplifier with Gain = 50

Low Distortion Power Wienbridge Oscillator

DS006976-6

DS006976-7

Amplifier with Bass Boost

Square Wave Oscillator

DS006976-8

DS006976-9

www.national.com

Typical Applications (Continued)

Frequency Response with Bass Boost

DS006976-10

AM Radio Power Amplifier

DS006976-11

Note 4: Twist Supply lead and supply ground very tightly.

Note 5: Twist speaker lead and ground very tightly.

Note 6: Ferrite bead in Ferroxcube K5-001-001/3B with 3 turns of wire.

Note 7: R1C1 band limits input signals.

Note 8: All components must be spaced very closely to IC.

www.national.com

Physical Dimensions inches (millimeters) unless otherwise noted

SO Package (M)

Order Number LM386M-1

NS Package Number M08A

www.national.com

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

8-Lead (0.118” Wide) Molded Mini Small Outline Package

Order Number LM386MM-1

NS Package Number MUA08A

www.national.com

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

Dual-In-Line Package (N)

Order Number LM386N-1, LM386N-3 or LM386N-4

NS Package Number N08E

LIFE SUPPORT POLICY

NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT

DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL

COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or

systems which, (a) are intended for surgical implant

into the body, or (b) support or sustain life, and

whose failure to perform when properly used in

accordance with instructions for use provided in the

labeling, can be reasonably expected to result in a

significant injury to the user.

2. A critical component is any component of a life

support device or system whose failure to perform

can be reasonably expected to cause the failure of

the life support device or system, or to affect its

safety or effectiveness.

National Semiconductor

Corporation

Americas

Tel: 1-800-272-9959

Fax: 1-800-737-7018

Email: support@nsc.com

National Semiconductor

Europe

National Semiconductor

Asia Pacific Customer

Response Group

Tel: 65-2544466

Fax: 65-2504466

National Semiconductor

Japan Ltd.

Tel: 81-3-5639-7560

Fax: 81-3-5639-7507

Fax: +49 (0) 180-530 85 86

Email: europe.support@nsc.com

Deutsch Tel: +49 (0) 69 9508 6208

English Tel: +44 (0) 870 24 0 2171

Français Tel: +33 (0) 1 41 91 8790

Email: ap.support@nsc.com

www.national.com

National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements,

and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should

obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are

sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.

TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard

warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where

mandated by government requirements, testing of all parameters of each product is not necessarily performed.

TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and

applications using TI components. To minimize the risks associated with customer products and applications, customers should provide

adequate design and operating safeguards.

TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right,

or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information

published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a

warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual

property of the third party, or a license from TI under the patents or other intellectual property of TI.

Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied

by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive

business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional

restrictions.

Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all

express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not

responsible or liable for any such statements.

TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably

be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing

such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and

acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products

and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be

provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in

such safety-critical applications.

TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are

specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military

specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at

the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use.

TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are

designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated

products in automotive applications, TI will not be responsible for any failure to meet such requirements.

Following are URLs where you can obtain information on other Texas Instruments products and application solutions:

Products

Audio

Applications

www.ti.com/audio

amplifier.ti.com

dataconverter.ti.com

www.dlp.com

Communications and Telecom www.ti.com/communications

Amplifiers

Data Converters

DLP® Products

DSP

Computers and Peripherals

Consumer Electronics

Energy and Lighting

Industrial

www.ti.com/computers

www.ti.com/consumer-apps

www.ti.com/energy

dsp.ti.com

www.ti.com/industrial

www.ti.com/medical

www.ti.com/security

Clocks and Timers

Interface

www.ti.com/clocks

interface.ti.com

logic.ti.com

Medical

Security

Logic

Space, Avionics and Defense www.ti.com/space-avionics-defense

Transportation and Automotive www.ti.com/automotive

Power Mgmt

Microcontrollers

RFID

power.ti.com

microcontroller.ti.com

www.ti-rfid.com

Video and Imaging

www.ti.com/video

OMAP Mobile Processors www.ti.com/omap

Wireless Connectivity www.ti.com/wirelessconnectivity

TI E2E Community Home Page

e2e.ti.com

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265

LM386 [TI]

相关型号：

SI9130DB

SI9135LG-T1

SI9135LG-T1-E3

SI9135_11

SI9136_11

SI9130CG-T1-E3

SI9130LG-T1-E3

SI9130_11

SI9137

SI9137DB

SI9137LG

SI9122E