功放芯片0816、常用电子元器件芯片资料TDA7296A

TDA7296A 70V - 60W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY PRODUCT PREVIEW VERY HIGH OPERATING VOLTAGE RANGE (35V) DMOS POWERSTAGE HIGH OUTPUT POWER (UP TO 60W MUSIC POWER) MUTING/STAND-BY FUNCTIONS NO SWITCH ON/OFF NOISE NO BOUCHEROT CELLS VERYLOW DISTORTION VERYLOW NOISE SHORT CIRCUIT PROTECTION THERMALSHUTDOWN CLIPPINGDETECTION OUTPUT DESCRIPTION The TDA7296A is a monolithic integrated circuit in Multiwatt15 package, intended for use as audio class AB amplifier in Hi-Fi field applications (Home Stereo, self powered loudspeakers, Top- class TV). Thanks to the wide voltage range and to the high out current capability it is able to sup- ply the highest power into both 4 and 8 loads even in presence of poor supply regulation, with high Supply Voltage Rejection. The built in muting function with turn on delay simplifies the remote operation avoiding switching on-off noises. The device provides a circuit for the detection of clipping in the output stages. The output, on open collector, is able to drive system with automatic levelcontrol. This is preliminaryinformation on a new productnow in development.Details are subject to change without notice. June 1996 IN-2 R2 680 C2 22F C1 470nF IN+ R1 22K 3 R3 22K - + MUTE STBY 4 VM VSTBY 10 9 IN+MUTE MUTE STBY R4 22K THERMAL SHUTDOWN S/C PROTECTION R5 10K C3 10FC4 10F 1 STBY-GND C5 22F 713 14 6 158 -Vs-PWVs BOOTSTRAP OUT +PWVs+Vs C9 100nFC8 1000F -Vs D96AU494 +VsC7 100nFC6 1000F CD 5 +5V Figure 1: Typical Applicationand Test Circuit Multiwatt 15 ORDERING NUMBER: TDA7296AV MULTIPOWER BCD TECHNOLOGY 1/13 + + - + - + CD BOOTSTRAP IN+ IN- +VS BOOTSTRAP OUTPUT CD -VS BIPOLAR TRANSCONDUCTANCE INPUT STAGE MOS GAIN Rg= 50 ; Tamb= 25C, f = 1 kHz; unlessotherwise specified. SymbolParameterTestConditionMin.Typ.Max.Unit VSOperating Supply Range1035V IqQuiescent Current203060mA IbInput Bias Current500nA VOSInput Offset Voltage+10mV IOSInput Offset Current+100nA PORMS Continuous Output Powerd = 0.5%: VS= 24V, RL= 8 VS= 21V, RL= 6 S= 18V, RL= 4 27 27 27 30 30 30 W W W Music Power (RMS) (*) t = 1s d = 10%; RL= 8 ; VS= 29V RL= 6 ; VS= 24V RL= 4;VS= 22V 60 60 60 W W W dTotal Harmonic Distortion (*)PO= 5W; f = 1kHz PO= 0.1to 20W; f = 20Hzto 20kHz 0.005 0.1 % % VS= 18V, RL= 4: PO= 5W; f = 1kHz PO= 0.1to 20W; f = 20Hzto 20kHz 0.01 0.1 % % SRSlew Rate710V/s GVOpen Loop Voltage Gain80dB GVClosed Loop Voltage Gain243040dB eNTotal Input NoiseA = curve f = 20Hz to 20kHz 1 25 V V fL, fHFrequency Response (-3dB)PO= 1W20Hz to 20kHz RiInput Resistance100k SVRSupply Voltage Rejectionf = 100Hz; Vripple= 0.5Vrms6075dB TSThermal Shutdown145 C STAND-BY FUNCTION (Ref: -VSor GND) VST onStand-by on Threshold1.5V VST offStand-by off Threshold3.5V ATTst-byStand-by Attenuation7090dB Iq st-byQuiescent Current Stand-by13mA MUTE FUNCTION (Ref: -VSor GND) VMonMute on Threshold1.5V VMoffMute off Threshold3.5V ATTmuteMute AttenuatIon6080dB DC OffClipping detector OFF. CD output Duty Cycle THD = 1%TBD% DC OnClipping detector On. CD output Duty Cycle THD = 10%TBD% Note (*): MUSIC POWER is the maximalpower which the amplifieris capableof producingacross the rated load resistance (regardless of nonlinearity) 1 sec after the application of a sinusoidal input signal of frequency 1KHz. Note (*): Tested with optimized Application Board (see fig. 2) TDA7296A 3/13 Figure 2: P.C.B.and components layout of the circuit of figure 1. (1:1 scale) Note: The Stand-by andMute functions can be referred eitherto GND or -VS. On theP.C.B. is possible to set both the configuration through the jumper J1. TDA7296A TDA7296A 4/13 APPLICATION SUGGESTIONS (seeTest and ApplicationCircuits of the Fig. 1) The recommended values of the external components are those shown on the application circuit of Fig- ure 1. Different values can be used; the following table can help the designer. COMPONENTSSUGGESTED VALUEPURPOSE LARGER THAN SUGGESTED SMALLER THAN SUGGESTED R1 (*)22kINPUT RESISTANCEINCREASE INPUT IMPRDANCE DECREASE INPUT IMPEDANCE R2680CLOSED LOOP GAIN SET TO 30dB (*) DECREASE OF GAININCREASE OF GAIN R3 (*)22kINCREASE OF GAINDECREASE OF GAIN R422kST-BY TIME CONSTANT LARGER ST-BY ON/OFF TIME SMALLER ST-BY ON/OFF TIME; POP NOISE R510kMUTE TIME CONSTANT LARGER MUTE ON/OFF TIME SMALLER MUTE ON/OFF TIME C10.47FINPUT DC DECOUPLING HIGHER LOW FREQUENCY CUTOFF C222FFEEDBACK DC DECOUPLING HIGHER LOW FREQUENCY CUTOFF C310FMUTE TIME CONSTANT LARGER MUTE ON/OFF TIME SMALLER MUTE ON/OFF TIME C410FST-BY TIME CONSTANT LARGER ST-BY ON/OFF TIME SMALLER ST-BY ON/OFF TIME; POP NOISE C522FBOOTSTRAPPINGSIGNAL DEGRADATION AT LOW FREQUENCY C6, C81000FSUPPLY VOLTAGE BYPASS DANGER OF OSCILLATION C7, C90.1FSUPPLY VOLTAGE BYPASS DANGER OF OSCILLATION (*) R1 = R3 FOR POP OPTIMIZATION (*) CLOSED LOOP GAINHAS TO BE 24dB TDA7296A 5/13 Figure 3: OutputPower vs. Supply Voltage. Figure 5: OutputPower vs. Supply Voltage Figure4: Distortionvs. Output Power Figure8: Distortionvs. Frequency TYPICALCHARACTERISTICS (ApplicationCircuit of fig 1 unlessotherwise specified) Figure6: Distortionvs. Output Power Figure 7: Distortion vs. Frequency TDA7296A 6/13 Figure14: PowerDissipation vs. Output Power Figure 13: Power Dissipation vs. OutputPower Figure 11: MuteAttenuationvs. Vpin10 Figure12: St-byAttenuationvs. Vpin9 Figure10:SupplyVoltageRejectionvs.Frequency TYPICALCHARACTERISTICS (continued) Figure 9: QuiescentCurrent vs. Supply Voltage TDA7296A 7/13 INTRODUCTION In consumer electronics, an increasing demand has arisen for very high power monolithic audio amplifiers able to match, with a low cost the per- formance obtained from the best discrete de- signs. The task of realizing this linear integrated circuit in conventional bipolar technology is made ex- tremely difficult by the occurence of 2nd break- down phenomenon. It limits the safe operating area (SOA) of the power devices, and as a con- sequence, the maximum attainableoutput power, especially in presence of highly reactive loads. Moreover, full exploitation of the SOA translates into a substantial increase in circuit and layout complexity due to the need for sophisticated pro- tection circuits. To overcome these substantial drawbacks, the use of power MOS devices, which are immune from secondarybreakdownis highly desirable. The device described has therefore been devel- oped in a mixed bipolar-MOS high voltage tech- nology called BCD 80. 1) Output Stage The main design task one is confrontedwith while developing an integrated circuit as a power op- erational amplifier, independently of the technol- ogy used, is that of realising the outputstage. The solution shown as a principle schematic by Fig 15 represents the DMOS unity-gain output buffer of the TDA7296A. This large-signal, high-power buffer must be ca- pable of handling extremely high current and volt- age levels while maintaining acceptably low har- monic distortion and good behaviour over fre- quency response; moreover, an accurate control of quiescentcurrent is required. A local linearizing feedback, provided by differen- tial amplifier A, is used to fullfil the above require- ments, allowing a simple and effective quiescent current setting. Proper biasing of the power output transistors alone is howevernot enoughto guaranteethe ab- senceof crossover distortion. While a linearization of the DC transfer charac- teristic of the stage is obtained, the dynamic be- haviour of the system must be takeninto account. A significant aid in keeping the distortion contrib- uted by the final stage as low as possible is pro- vided by the compensation scheme, which ex- ploits the direct connection of the Miller capacitor at the amplifiers output to introduce a local AC feedbackpath enclosing the output stage itself. 2) Protections In designing a power IC, particular attention must be reserved to the circuits devoted to protection of the device from short circuit or overload condi- tions. Due to the absence of the 2nd breakdown phe- nomenon, the SOA of the power DMOS transis- tors is delimited only by a maximum dissipation curve dependent on the duration of the applied stimulus. In order to fully exploit the capabilities of the power transistors, the protection scheme imple- mented in this device combines a conventional SOA protection circuit with a novel local tempera- ture sensing technique which ” dynamically” con- trols the maximumdissipation. Figure 15: PrincipleSchematicof a DMOSunity-gain buffer. TDA7296A 8/13 In addition to the overload protection described above, the device features a thermal shutdown circuit which initially puts the device into a muting state ( Tj = 145 oC) and then into stand-by ( Tj = 150 oC). Full protection against electrostatic discharges on everypin is included. 3) OtherFeatures The device is provided with both stand-by and mute functions, independently driven by two CMOS logiccompatible input pins. The circuits dedicated to the switching on and off of the amplifier have been carefully optimized to avoid any kindof uncontrolledaudibletransient at the output. The sequence that we recommend during the ON/OFFtransients is shown by Figure 16. The application of figure 17 shows the possibility of using only one command for both st-by and mute functions. On both the pins, the maximum applicable range corresponds to the operating supply voltage. 1N4148 10K30K 20K 10F10F MUTESTBY D93AU014 MUTE/ ST-BY Figure 17: SingleSignal ST-BY/MUTE Control Circuit PLAY OFF ST-BY MUTEMUTE ST-BYOFF D93AU013 5V 5V +Vs (V) +35 -35 VMUTE PIN #10 (V) VST-BY PIN #9 (V) -Vs VIN (mV) IP (mA) VOUT (V) Figure 16: TurnON/OFF SuggestedSequence TDA7296A 9/13 BRIDGEAPPLICATION Another application suggestion is the BRIDGE configuration, where two TDA7296A are used, as shown by the schematic diagram of figure 19. In this application, the value of the load must not be lower than 8 Ohm for dissipation and current capabilityreasons. A suitable field of application includes HI-FI/TV subwoofersrealizations. The main advantagesoffered by this solution are: - High power performanceswith limited supply voltagelevel. - Considerablyhigh outputpower even with high loadvalues (i.e. 16 Ohm). The characteristics shown by figures 21 and 22, measured with loads respectively 8 Ohm and 16 Ohm. With Rl= 8 Ohm, Vs = 18V the maximum output power obtainable is 60W, while with Rl=16 Ohm, Vs = 24V the maximumPout is 60W. 22K0.56F 2200F0.22F + - 22F 22K 680 22K 3 1 4 137 +Vs Vi 815 2 14 6 10 9 + - 3 0.56F22K 1 4 2 14 6 22F 22K 680 10 9 22F 158 -Vs 2200F0.22F 22F 20K 10K30K 1N4148 ST-BY/MUTE 137 D96AU497 Figure 19: BridgeApplication Circuit 4) ClippingDetector Output The TDA7296A is equipped with an internal cir- cuit able to detectthe output stage saturation pro- viding a proper current sinking into on open col- lector output (pin 5) when a certain distortionlevel is reachedat output. This particular function allows gain compression facility whenever the amplifier is overdriven, thus obtaining high quality soundall listeninglevels. VO ICLIP OUTPUT SIGNAL tS96AU498 Figure 18: Clipping DetectorOutput Waveform TDA7296A 10/13 Figure21: Distortionvs. Output Power Figure 20: FrequencyResponseof the Bridge Application Figure 22: Distortionvs. Output Power TDA7296A 11/13 DIM. mminch MIN.TYP.MAX.MIN.TYP.MAX. A50.197 B2.650.104 C1.60.063 D10.039 E0.490.550.0190.022 F0.660.750.0260.030 G1.141.271.40.0450.0500.055 G117.5717.7817.910.6920.7000.705 H119.60.772 H220.20.795 L22.122.60.8700.890 L12222.50.8660.886 L217.6518.10.6950.713 L317.2517.517.750.6790.6890.699 L410.310.710.90.4060.4210.429 L72.