LM386
Low Voltage Audio Power Amplifier
General Description
The LM386is a power amplifier designed for u in low volt-age consumer applications.The gain is internally t to 20to keep external part count low,but the addition of an external resistor and capacitor between pins 1and 8will increa the gain to any value up to 200.
The inputs are ground referenced while the output is auto-matically biad to one half the supply voltage.The quies-cent power drain is only 24milliwatts when operating from a 6volt supply,making the LM386ideal for battery operation.
Features
n Battery operation
n Minimum external parts
n Wide supply voltage range:4V–12V or 5V–18V n Low quiescent current drain:4mA n Voltage gains from 20to 200n Ground referenced input
n Self-centering output quiescent voltage n Low distortion
n
Available in 8pin MSOP package
Applications
n AM-FM radio amplifiers
n Portable tape player amplifiers n Intercoms
n TV sound systems n Line drivers有什么好玩的单机游戏
n Ultrasonic drivers n Small rvo drivers n
Power converters
Equivalent Schematic and Connection Diagrams
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Small Outline,
Molded Mini Small Outline,and Dual-In-Line Packages
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Top View
Order Number LM386M-1,LM386MM-1,LM386N-1,LM386N-3or LM386N-4See NS Package Number M08A,MUA08A or N08E
January 2000
LM386Low Voltage Audio Power Amplifier
©2000National Semiconductor Corporation
Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,plea contact the National Semiconductor Sales Office/Distributors for availability and specifications.Supply Voltage
(LM386N-1,-3,LM386M-1)15V Supply Voltage (LM386N-4)22V
Package Dissipation (Note 3)(LM386N) 1.25W (LM386M)0.73W (LM386MM-1)0.595W Input Voltage
±0.4V
Storage Temperature −65˚C to +150˚C
Operating Temperature 0˚C to +70˚C
Junction Temperature +150˚C
Soldering Information
Dual-In-Line Package Soldering (10c)+260˚C Small Outline Package (SOIC and MSOP)Vapor Pha (60c)+215˚C Infrared (15c)+220˚C See AN-450“Surface Mounting Methods and Their Eff
ect on Product Reliability”for other methods of soldering surface mount devices.Thermal Resistance
θJC (DIP)
37˚C/W θJA (DIP)
107˚C/W θJC (SO Package)
35˚C/W θJA (SO Package)
172˚C/W θJA (MSOP)
210˚C/W θJC (MSOP)
56˚C/W Electrical Characteristics (Notes 1,2)
最新创业项目
T A =25˚C
Parameter
Conditions Min Typ Max Units Operating Supply Voltage (V S )
LM386N-1,-3,LM386M-1,LM386MM-1412V LM386N-4
5
18
V Quiescent Current (I Q )V S =6V,V IN =0
48
mA Output Power (P OUT )
LM386N-1,LM386M-1,LM386MM-1V S =6V,R L =8Ω,THD =10%250325mW LM386N-3V S =9V,R L =8Ω,THD =10%500700mW LM386N-4V S =16V,R L =32Ω,THD =10%700
1000mW Voltage Gain (A V )V S =6V,f =1kHz
26dB 10µF from Pin 1to 8
46dB Bandwidth (BW)
V S =6V,Pins 1and 8Open
控制的英语
300kHz Total Harmonic Distortion (THD)V S =6V,R L =8Ω,P OUT =125mW 0.2%f =1kHz,Pins 1and 8Open Power Supply Rejection Ratio (PSRR)V S =6V,f =1kHz,C BYPASS =10µF 50dB Pins 1and 8Open,Referred to Output
Input Resistance (R IN )50k ΩInput Bias Current (I BIAS )
V S =6V,Pins 2and 3Open
250
nA
Note 1:All voltages are measured with respect to the ground pin,unless otherwi 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 bad 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.
穿衣颜色搭配
L M 386
周姓的来源和历史
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Application Hints
GAIN CONTROL
To make the LM386a more versatile amplifier,two pins(1 and8)are provided for gain control.With pins1and8open the1.35kΩresistor ts the gain at20(26dB).If a capacitor is put from pin1to8,bypassing the1.35kΩresistor,the gain will go up to200(46dB).If a resistor is placed in ries with the capacitor,the gain can be t to any value from20 to200.Gain control can also be done by capacitively cou-pling a resistor(or FET)from pin1to ground.
Additional external components can be placed in parallel with the internal feedback resistors to tailor the gain and fre-quency respon for individual applications.For example, we can compensate poor
speaker bass respon by fre-quency shaping the feedback path.This is done with a ries RC from pin1to5(paralleling the internal15kΩresistor). For6dB effective bass boost:R≅15kΩ,the lowest value for good stable operation is R=10kΩif pin8is open.If pins 1and8are bypasd then R as low as2kΩcan be ud. This restriction is becau the amplifier is only compensated for clod-loop gains greater than9.
INPUT BIASING
The schematic shows that both inputs are biad to ground
with a50kΩresistor.The ba current of the input transis-
tors is about250nA,so the inputs are at about12.5mV
when left open.If the dc source resistance driving the LM386
is higher than250kΩit will contribute very little additional
offt(about2.5mV at the input,50mV at the output).If the
dc source resistance is less than10kΩ,then shorting the
unud input to ground will keep the offt low(about2.5mV
at the input,50mV at the output).For dc source resistances
between the values we can eliminate excess offt by put-
ting a resistor from the unud input to ground,equal in
value to the dc source resistance.Of cour all offt prob-
lems are eliminated if the input is capacitively coupled.
When using the LM386with higher gains(bypassing the
1.35kΩresistor between pins1and8)it is necessary to by-
pass the unud input,preventing degradation of gain and
possible instabilities.This is done with a0.1µF capacitor or
a short to ground depending on the dc source resistance on
the driven input.
LM386
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Typical Performance Characteristics
Quiescent Supply Current vs Supply Voltage
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Power Supply Rejection Ratio (Referred to the Output)vs Frequency
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Peak-to-Peak Output Voltage Swing vs Supply Voltage
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Voltage Gain vs Frequency DS006976-14Distortion vs Frequency DS006976-15Distortion vs Output Power
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Device Dissipation vs Output Power —4ΩLoad DS006976-17
Device Dissipation vs Output Power —8ΩLoad DS006976-18Device Dissipation vs Output Power —16ΩLoad
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L M 386
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Typical Applications
关于春天的现代诗Amplifier with Gain =20
Minimum Parts
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Amplifier with Gain =200
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Amplifier with Gain =50DS006976-6
Low Distortion Power Wienbridge Oscillator
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Amplifier with Bass Boost DS006976-8
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Square Wave Oscillator
DS006976-9初学吉他
LM386
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