LM4843 Boomer (R) Audio Power Amplifier Series General DescriptionKey SpecificationsFeaturesApplications Block DiagramFIGURE 1. LM4843 Block Diagram Connection DiagramAbsolute Maximum RatingsOperating RatingsElectrical Characteristics for Entire ICElectrical Characteristics for Volume AttenuatorsElectrical Characteristics for Bridged Mode OperationTypical ApplicationFIGURE 2. Typical Application Circuit Typical Performance CharacteristicsApplication InformationEXPOSED-DAP PACKAGE PCB MOUNTING CONSIDERATIONSPCB LAYOUT AND SUPPLY REGULATION CONSIDERATIONS FOR DRIVING 3Ohm AND 4Ohm LOADSBRIDGE CONFIGURATION EXPLANATIONPOWER DISSIPATIONPOWER SUPPLY BYPASSINGSELECTING PROPER EXTERNAL COMPONENTSInput Capacitor Value SelectionOPTIMIZING CLICK AND POP REDUCTION PERFORMANCE MICRO-POWER SHUTDOWNDC VOLUME CONTROLVolume Control Table ( Table 2 ) AUDIO POWER AMPLIFIER DESIGN Recommended Printed Circuit Board LayoutAnalog Audio LM4843 MSOP Eval Board Assembly Part Number: 980011373-100 Revision: A Bill of MaterialLM4843MH Demo BoardsPhysical DimensionsLM4843Stereo 2W Audio Power Amplifierswith DC Volume ControlGeneral DescriptionThe LM4843 is a monolithic integrated circuit that providesDC volume control, and stereo bridged audio power amplifi-ers capable of producing 2W into 4Ω (Note 1) with less than1.0% THD or 2.2W into 3Ω (Note 2) with less than 1.0%THD.Boomer®audio integrated circuits were designed specificallyto provide high quality audio while requiring a minimumamount of external components. The LM4843 incorporates aDC volume control with stereo bridged audio power amplifi-ers making it optimally suited for multimedia monitors, por-table radios, desktop, and portable computer applications.The LM4843 features an externally controlled, low-powerconsumption shutdown mode, and both a power amplifierand headphone mute for maximum system flexibility andperformance.Note 1: When properly mounted to the circuit board, the LM4843MH willdeliver 2W into 4Ω. See the Application Information section for LM4843MHusage information.Note 2: LM4843MH that has been properly mounted to the circuit board andforced-air cooled will deliver 2.2W into 3Ω.Key Specificationsn POat 1% THD+Nn into 3Ω 2.2W (typ)n into 4Ω 2.0W (typ)n into 8Ω 1.1W (typ)n Shutdown current 0.7µA (typ)Featuresn Acoustically Enhanced DC Volume Control Tapern Stereo bridged power amplifiersn “Click and pop” suppression circuitryn Thermal shutdown protection circuitryApplicationsn Portable and Desktop Computersn Multimedia Monitorsn Portable Radios, PDAs, and Portable TVsBlock DiagramBoomer®is a registered trademark of NationalSemiconductor Corporation.20038389FIGURE 1. LM4843 Block DiagramJuly 2002LM4843 Stereo 2W Audio Power Amplifiers with DC Volume Control© 2002 National Semiconductor Corporation DS200383 www.national.comConnection DiagramStandard LM4843MH20038387Top ViewOrder Number LM4843MHSee NS Package Number MXA20LM4843www.national.com 2Absolute Maximum Ratings (Note 10)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 Internally limitedESD Susceptibility (Note 12) 2000VESD Susceptibility (Note 13) 200VJunction Temperature 150˚CSoldering InformationSmall Outline PackageVapor Phase (60 sec.) 215˚CInfrared (15 sec.) 220˚CSee AN-450 “Surface Mounting and their Effects onProduct Reliability” for other methods of soldering surfacemount devices.θJC(typ) — MXA20A 2˚C/WθJA(typ) — MXA20A (exposedDAP) (Note 4)41˚C/WθJA(typ) — MXA20A (exposedDAP) (Note 3)54˚C/WθJA(typ) — MXA20A (exposedDAP) (Note 5)59˚C/WθJA(typ) — MXA20A (exposedDAP) (Note 6)93˚C/WOperating RatingsTemperature RangeTMIN≤ TA≤TMAX−40˚C ≤TA ≤ 85˚CSupply Voltage 2.7V≤ VDD≤ 5.5VElectrical Characteristics for Entire IC(Notes 7, 10) The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25˚C.Symbol Parameter ConditionsLM4843Units(Limits)Typical(Note 14)Limit(Note 15)VDDSupply Voltage 2.7 V (min)5.5 V (max)IDDQuiescent Power Supply Current VIN= 0V, IO= 0A 15 30 mA (max)ISDShutdown Current Vshutdown=VDD0.7 2.0 µA (max)Electrical Characteristics for Volume Attenuators(Notes 7, 10) The following specifications apply for VDD= 5V. Limits apply for TA= 25˚C.Symbol Parameter ConditionsLM4843Units(Limits)Typical(Note 14)Limit(Note 15)CRANGEAttenuator Range (Note 16) Attenuation with VDCVol= 5V, No Load±0.75 dB (max)Attenuation with VDCVol= 0V -75 dB (min)AMMute Attenuation Vmute= 5V, Bridged Mode (BM) -78 dB (min)LM4843www.national.com3Electrical Characteristics for Bridged Mode Operation(Notes 7, 10) The following specifications apply for VDD= 5V, unless otherwise noted. Limits apply for TA= 25˚C.Symbol Parameter ConditionsLM4843Units(Limits)Typical(Note 14)Limit(Note 15)VOSOutput Offset Voltage VIN= 0V, No Load 10±50 mV (max)POOutput Power THD+N=1.0%; f=1kHz; RL=3Ω(Note 8)2.2 WTHD+N=1.0%; f=1kHz; RL=4Ω(Note 9)2WTHD = 1% (max);f = 1 kHz;RL=8Ω1.1 1.0 W (min)THD+N = 10%;f = 1 kHz; RL=8Ω 1.5 WTHD+N Total Harmonic Distortion+Noise PO= 1W, 20 Hz<f<20 kHz,RL=8Ω,AVD=20.3 %PO= 340 mW, RL=32Ω 1.0 %PSRR Power Supply Rejection Ratio CB= 1.0 µF, f = 120 Hz,VRIPPLE= 200 mVrms; RL=8Ω74 dBSNR Signal to Noise Ratio VDD= 5V, POUT= 1.1W, RL=8Ω,A-Wtd Filter93 dBXtalkChannel Separation f=1kHz, CB= 1.0 µF 70 dBNote 3: The θJAgiven is for an MXA20A package whose exposed-DAP is soldered to an exposed 2in2piece of 1 ounce printed circuit board copper.Note 4: The θJAgiven is for an MXA20A package whose exposed-DAP is soldered to a 2in2piece of 1 ounce printed circuit board copper on a bottom side layerthrough 21 8mil vias.Note 5: The θJAgiven is for an MXA20A package whose exposed-DAP is soldered to an exposed 1in2piece of 1 ounce printed circuit board copper.Note 6: The θJAgiven is for an MXA20A package whose exposed-DAP is not soldered to any copper.Note 7: All voltages are measured with respect to the ground pins, unless otherwise specified. All specifications are tested using the typical application as shownin Figure 1.Note 8: When driving 3Ω loads from a 5V supply the LM4843MH must be mounted to the circuit board and forced-air cooled.Note 9: When driving 4Ω loads from a 5V supply the LM4843MH must be mounted to the circuit board.Note 10: Absolute Maximum Ratings