LM4880 Boomer (R) Audio Power Amplifier Series General DescriptionKey SpecificationsFeaturesApplicationsConnection DiagramTypical ApplicationFIGURE 1. Typical Audio Amplifier Application Circuit Absolute Maximum RatingsOperating RatingsElectrical Characteristics (Notes , )Automatic Shutdown CircuitFIGURE 2. Automatic Shutdown Circuit Automatic Switching CircuitFIGURE 3. Automatic Switching Circuit External Components DescriptionTypical Performance CharacteristicsApplication InformationSHUTDOWN FUNCTIONPOWER DISSIPATIONPOWER SUPPLY BYPASSINGAUTOMATIC SHUTDOWN CIRCUITAUTOMATIC SWITCHING CIRCUITPROPER SELECTION OF EXTERNAL COMPONENTSSelection of Input and Output Capacitor SizeAUDIO POWER AMPLIFIER DESIGNDesign a Dual 200 mW/8Ohm Audio AmplifierLM4880 MDA MWA DUAL 250 MW AUDIO POWER AMPLIFIER WITH SHUTDOWN MODEDie/Wafer CharacteristicsPhysical DimensionsLM4880Dual 250 mW Audio Power Amplifier with ShutdownModeGeneral DescriptionThe LM4880 is a dual audio power amplifier capable ofdelivering typically 250mW per channel of continuous aver-age power to an 8Ω load with 0.1% THD+N using a 5Vpower supply.Boomer audio power amplifiers were designed specifically toprovide high quality output power with a minimal amount ofexternal components using surface mount packaging.Since the LM4880 does not require bootstrap capacitors orsnubber networks, it is optimally suited for low-power por-table systems.The LM4880 features an externally controlled, low-powerconsumption shutdown mode, as well as an internal thermalshutdown protection mechanism.The unity-gain stable LM4880 can be configured by externalgain-setting resistors.Key Specificationsn THD+N at 1kHz at 200mW continuous average outputpower into 8Ω: 0.1% (max)n THD+N at 1kHz at 85mW continuous average outputpower into 32Ω: 0.1% (typ)n Output power at 10% THD+N at 1kHz into 8Ω:325mW (typ)n Shutdown current: 0.7µA (typ)n 2.7V to 5.5V supply voltage rangeFeaturesn No bootstrap capacitors or snubber circuits arenecessaryn Small Outline (SO) and DIP packagingn Unity-gain stablen External gain configuration capabilityApplicationsn Headphone Amplifiern Personal Computersn CD-ROM PlayersConnection DiagramSmall Outline andDIP Packages01234302Top ViewOrder Number LM4880M or LM4880NSee NS Package Number M08A for SOor NS Package Number N08E for DIPBoomer®is a registered trademark of National Semiconductor Corporation.September 2004LM4880 Boomer Audio Power Amplifier Series Dual 250 mW Audio Power Amplifier withShutdown Mode© 2004 National Semiconductor Corporation DS012343 www.national.comTypical Application01234301*Refer to the Application Information section for information concerning proper selection of the input and output coupling capacitors.FIGURE 1. Typical Audio Amplifier Application CircuitLM4880www.national.com 2Absolute Maximum Ratings (Note 2)If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.Supply Voltage 6.0VStorage Temperature −65˚C to +150˚CInput Voltage −0.3V to VDD+0.3VPower Dissipation (Note 3) Internally limitedESD Susceptibility (Note 4) 2000VESD Susceptibility (Note 5) 200VJunction Temperature 150˚CSoldering InformationSmall Outline PackageVapor Phase (60 sec.)Infrared (15 sec.)215˚C220˚CSee AN-450 “Surface Mounting and their Effects onProduct Reliability” for other methods of soldering surfacemount devices.Thermal ResistanceθJC(DIP) 37˚C/WθJA(DIP) 107˚C/WθJC(SO) 35˚C/WθJA(SO) 170˚C/WOperating RatingsTemperature RangeTMIN≤TA≤TMAX−40˚C≤TA≤+85˚CSupply Voltage 2.7V≤VDD≤5.5VElectrical Characteristics (Notes 1, 2)The following specifications apply for VDD= 5V unless otherwise specified. Limits apply for TA= 25˚C.Symbol Parameter Conditions LM4880 Units(Limits)Typical Limit(Note 6) (Note 7)VDDSupply Voltage 2.7 V (min)5.5 V (max)IDDQuiescent Power Supply Current VIN=0V, IO=0A 3.6 6.0 mA(max)ISDShutdown Current VPIN5=VDD0.7 5 µA (max)VOSOutput Offset Voltage VIN=0V 5 50 mV(max)POOutput Power THD=0.1% (max); f=1 kHz;RL=8Ω 250 200 mW(min)RL=32Ω 85 mWTHD+N=10%; f=1 kHzRL=8Ω 325 mWRL=32Ω 110 mWTHD+N Total Harmonic Distortion+Noise RL=8Ω,PO=200 mW; 0.03 %RL=32Ω,PO=75 mW; 0.02 %f=1 kHzPSRR Power Supply Rejection Ratio CB= 1.0 µF,VRIPPLE=200 mVrms, f = 100 Hz50 dBNote 1: All voltages are measured with respect to the ground pin, unless otherwise specified.Note 2: Absolute Maximum Ratings indicate limits beyond which damage may occur. Operating Ratings indicate conditions for which the device is functional, butdo not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guaranteespecific 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: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature TA. The maximumallowable power dissipation is PDMAX=(TJMAX−TA)/θJAor the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4880, TJMAX= 150˚C,and the typical junction-to-ambient thermal resistance is 170˚C/W for package M08A and 107˚C/W for package N08E.Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor.Note 5: Machine model, 220 pF–240 pF discharged through all pins.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).LM4880www.national.com3Automatic Shutdown CircuitAutomatic Switching Circuit01234303FIGURE 2. Automatic Shutdown Circuit01234304FIGURE 3. Automatic Switching CircuitLM4880www.national.com 4External Components Description (Figure 1)Components Functional Description1. RiInverting input resistance which sets the closed-loop gain in conjunction with RF. This resistoralso forms a high pass filter with Ciat fc= 1/(2πRiCi).2. CiInput coupling capacitor which blocks the DC voltage at the amplifier’s input terminals. Alsocreates a high pass filter with Riat fc= 1/(2πRiCi). Refer to the section, Proper Selection ofExternal Components, for an explanation of how to determine the value of Ci.3. RFFeedback resistance which sets closed-loop gain in conjunction with Ri.4. CSSupply bypass
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