功放芯片0816、常用电子元器件芯片资料TDA7294SV

TDA7294S 100V - 100W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY VERY HIGH OPERATING VOLTAGE RANGE (45V) DMOS POWERSTAGE HIGH OUTPUT POWER (100W THD = 10%, RL= 8, VS= 40V MUSIC POWER) MUTING/STAND-BY FUNCTIONS NO SWITCH ON/OFF NOISE VERYLOW DISTORTION VERYLOW NOISE SHORT CIRCUIT PROTECTED (WITH NO IN- PUT SIGNALAPPLIED) THERMALSHUTDOWN CLIP DETECTOR MODULARITY (MORE DEVICES CAN BE EASILYCONNECTEDINPARALLELTO DRIVE VERY LOW IMPEDANCES) DESCRIPTION The TDA7294S 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 highestpowerinto both 4 and 8 loads. The built in muting function with turn on delay simplifies the remote operation avoiding switching on-off noises. Parallel mode is made possible by connecting more device through of pin11. High output power can be delivered to very low impedance loads, so optimizingthe thermaldissipation of the system. July 2000 IN-2 R2 680 C2 22F C1 470nF IN+ R1 22K 3 R3 22K - + MUTE STBY 4 VMUTE VSTBY 10 9 SGND 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 D97AU805A +Vs C7 100nFC6 1000F BUFFER DRIVER 11 BOOT LOADER 12 5 VCLIP CLIP DET (*) (*) see Applicationnote (*) for SLAVE function (*) Figure 1: Typical Applicationand Test Circuit Multiwatt15 ORDERING NUMBER: TDA7294SV MULTIPOWER BCD TECHNOLOGY 1/13 ABSOLUTE MAXIMUM RATINGS SymbolParameterValueUnit VSSupply Voltage (No Signal)50V V1VSTAND-BYGND Voltage Referred to -VS(pin 8)90V V2Input Voltage (inverting) Referred to -VS90V V2- V3Maximum Differential Inputs30V V3Input Voltage (non inverting) Referred to -VS90V V4Signal GND Voltage Referred to -VS90V V5Clip Detector Voltage Referred to -VS100V V6Bootstrap Voltage Referred to -VS100V V9Stand-by Voltage Referred to -VS100V V10Mute Voltage Referred to -VS100V V11Buffer Voltage Referred to -VS100V V12Bootstrap Loader Voltage Referred to -VS90V IOOutput PeakCurrent10A PtotPower Dissipation Tcase= 70C50W TopOperating Ambient Temperature Range0 to 70 C Tstg, TjStorage and Junction Temperature150 C 1 2 3 4 5 6 7 9 10 11 8 BUFFER DRIVER MUTE STAND-BY -VS(SIGNAL) +VS(SIGNAL) BOOTSTRAP CLIP AND SHORT CIRCUIT DETECTOR SIGNAL GROUND NON INVERTING INPUT INVERTING INPUT STAND-BY GND TAB CONNECTED TO PIN8 13 14 15 12 -VS(POWER) OUT +VS(POWER) BOOTSTRAP LOADER D97AU806 PIN CONNECTION (Topview) QUICK REFERENCE DATA SymbolParameterTest ConditionsMin.Typ.Max.Unit VSSupply Voltage Operating12 45V GLOOPClosed Loop Gain2645dB Ptot Output PowerVS= 40V; RL= 8; THD = 10%100W VS= 30V; RL= 4; THD = 10%100W SVRSupply Voltage Rejection75dB THERMAL DATA SymbolDescriptionTypMaxUnit Rth j-caseThermal Resistance Junction-case11.5C/W TDA7294S 2/13 ELECTRICALCHARACTERISTICS (Refer to the Test Circuit VS= 35V, RL= 8, GV= 30dB; Rg= 50 ; Tamb= 25C, f = 1 kHz; unlessotherwise specified). SymbolParameterTestConditionMin.Typ.Max.Unit VSOperating Supply Range1245V IqQuiescent Current203060mA IbInput Bias Current500nA VOSInput Offset Voltage10mV IOSInput Offset Current100nA PORMS Continuous Output Powerd = 0.5%: VS= 35V, RL= 8 VS= 32V, RL= 6 VS= 28V, RL= 4 60 60 60 70 70 70 W W W Music Power (RMS) (*) t = 1s d = 10%; RL= 8 ; VS= 40V RL= 6 ; VS= 35V RL= 4;VS= 30V (*) 100 100 100 W W W dTotal Harmonic Distortion (*)PO= 5W; f = 1kHz PO= 0.1to 20W; f = 20Hzto 20kHz 0.005 0.1 % % VS= 28V, RL= 4: PO= 5W; f = 1kHz PO= 0.1to 20W; f = 20Hzto 20kHz 0.01 0.1 % % IMAXOvercurrent Protection ThresholdVS 40V6.5A SRSlew Rate710V/s GVOpen Loop Voltage Gain80dB GVClosed Loop Voltage Gain263045dB eNTotal Input NoiseA = curve f = 20Hz to 20kHz 1 25 V V fL, fHFrequency Response (-3dB)PO= 1W20Hz to 20kHz RiInput Resistance100 k SVRSupply Voltage Rejectionf = 100Hz; Vripple= 0.5Vrms6075dB TSThermal Shutdown150C 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 Note (*): MUSIC POWERCONCEPT 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) Note (*): Limited by the max. allowable current. Note (*): For supply voltage 35V, The device could be demaged in short circuit conditions when the inputsignal is applied TDA7294S 3/13 Figure 2: Typical Application P.C. Board and ComponentLayout (scale1:1) TDA7294S 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 IMPEDANCE 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 C522FXN (*)BOOTSTRAPPINGSIGNAL DEGRADATION AT LOW FREQUENCY C6, C81000FSUPPLY VOLTAGE BYPASS C7, C90.1FSUPPLY VOLTAGE BYPASS DANGER OF OSCILLATION (*) R1 = R3 for pop optimization (*) Closed Loop Gain has to be 26dB (*) Multiply this value for the number of modularpart connected MASTER UNDEFINED SLAVE -VS+3V -VS+1V -VS D98AU821 Slave function: pin 4 (Ref to pin 8 -VS) Note: If in the application, the speakers are connected via long wires, it is a good rule to add between the output and GND, a BoucherotCell, in order to avoid dangerous spurious oscillations when the speakersterminal are shorted. The suggested Boucherot Resistor is 3.9/2W and the capacitoris 1F. TDA7294S 5/13 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 phoenomenon. 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 of 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 BCDII 100. 1) Output Stage The main design task in developpinga power op- erational amplifier, independently of the technol- ogy used, is that of realizationof the output stage. The solution shown as a principle shematic by Fig3 represents the DMOSunity - gain output buffer of the TDA7294S. This large-signal, high-power buffer must be ca- pable of handling extremely high current and volt- age levels while maintaining acceptably low har- monicdistortionandgoodbehaviourover frequency response; moreover, an accurate con- trol 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 3: PrincipleSchematicof a DMOSunity-gain buffer. TDA7294S 6/13 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 = 150 oC) and then into stand-by ( Tj = 160 oC). Full protection against electrostatic discharges on every pinis 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 4. The application of figure 5 shows the possibility of using only one command for both st-by and mute functions. On both the pins, the maximum appli- cable range corresponds to the operating supply voltage. APPLICATION INFORMATION HIGH-EFFICIENCY Constraints of implementing high power solutions are the power dissipation and the size of the power supply. These are both due to the low effi- ciency of conventional AB class amplifier ap- proaches. Here below (figure 6) is described a circuit pro- posal for a high efficiency amplifier which can be adopted for both HI-FI and CAR-RADIO applica- tions. 1N4148 10K30K 20K 10F10F MUTESTBY D93AU014 MUTE/ ST-BY Figure 5: SingleSignal ST-BY/MUTE Control Circuit PLAY OFF ST-BY MUTEMUTE ST-BYOFF D98AU817 5V 5V +Vs (V) +40 -40 VMUTE PIN #10 (V) VST-BY PIN #9 (V) -Vs VIN (mV) IQ (mA) VOUT (V) Figure 4: Turn ON/OFF SuggestedSequence TDA7294S 7/13 The TDA7294S is a monolithicMOS power ampli- fier which can be operated at 90V supply voltage (100V with no signal applied) while delivering out- put currentsup to 6.5 A. This allows the use of this device as a very high power amplifier (up to 100W as peak power with T.H.D.=10 % and Rl = 4 Ohm); the only drawback is the power dissipation, hardly manageable in the above power range. The typical junction-to-case thermal resistance of the TDA7294S is 1 oC/W(max= 1.5oC/W). To avoid that, in worst case conditions, the chip temperature exceedes 150 oC, the thermal resis- tance of the heatsink must be 0.038 oC/W ( max ambient temperatureof 50 oC). As the above value is pratically unreachable; a high efficiency system is needed in those cases where the continuousRMS output power is higher than50-60 W. The TDA7294S was designed to work also in higher efficiencyway. For this reason there are four power supply pins: two intended for the signal part and two for the power part. T1 and T2 are two powertransistors thatonly operate when the output power reaches a certain threshold (e.g. 20 W). If the output power in- creases, these transistors are switched on during the portion of the signal where more output volt- age swing is needed, thus ”bootstrapping” the power supply pins(#13 and #15). The current generators formed by T4, T7, zener diodes Z1, Z2 and resistors R7,R8 define the minimum drop across the power MOS transistors of the TDA7294S. L1, L2, L3 and the snubbers C9, R1 and C10, R2 stabilize the loopsformed by the ”bootstrap”circuits and the output stage of the TDA7294S. By considering again a maximum average output power (music signal) of 20W, in case of the high efficiency application, the thermal resistance value needed from the heatsink is 2.2oC/W (Vs =45V and Rl= 8Ohm). All components (TDA7294S and power tran- sistorsT1and T2)can be placed ona 1.5oC/W heatsink, with the power darlingtons electrically insulated from the heatsink. Since the total power dissipation is less than that of a usual class AB amplifier, additional cost sav- ings can be obtained while optimizing the power supply, even with a high heatsink. BRIDGE APPLICATION Another application suggestion is the BRIDGE configuration,where two TDA7294S are used. In this application, the value of the load must not be lower than 8Ohm for dissipation and current capability reasons. 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). With Rl= 8 Ohm, Vs = 25V the maximum output power obtainable is 150 W, while with Rl=16 Ohm, Vs = 40V the maximum Pout is 200W (Music Power). APPLICATION NOTE: (ref. fig.7) Modular Application(more Devices in Parallel) The use of the modular application lets very high power be delivered to very low impedance loads. The modular application implies one device to act as a master and the others as slaves. The slave power stages are driven by the master device and work in parallel all together, while the input and the gain stages of the slave device are disabled, the figure below shows the connections required to configure two devices to work to- gether. The master chip connections are the same as the normal single ones. The outputs can be connected together with- out the need of any ballast resistance. The slave SGND pin must be tied to the nega- tive supply. The slave ST-BY pin must be connected to ST-BYpin. The bootstrap lines must be connected to- gether and the bootstrap capacitor must be in- creased: for N devices the boostrap capacitor must be 22F times N. The slave Mute and IN-pins must be grounded. THE BOOTSTRAP CAPACITOR For compatibility purpose with the previous de- vices of the family, the boostrap capacitor can be connectedboth between the bootstrappin (6) and the output pin (14) or between the boostrap pin (6) and the bootstraploaderpin (12). When the bootcap is connected between pin 6 and 14, the maximum supply voltage in presence of output signal is limited to 80V, due the boot- strap capacitor overvoltage. When the bootcap is connected between pins 6 and 12 the maximum supply voltageextend to the full voltage that the technologycan stand:100V. This is accomplished by the clamp introduced at the bootstrap loader pin (12): this pin follows the output voltage up to 100V and remains clamped at 100V. This feature lets the output voltage swing up to a gate-source voltage from the posi- tive supply (VS-3 to 6V) TDA7294S 8/13 3 1 4 137 815 2 14 6 10 R3 680 C11 22F L3 5H R18 270 R16 13K C15 22F 9 R12 13K C13 10F R13 20K C12 330nF R15 10K C14 10F R14 30K D5 1N4148 PLAY ST-BY R17 270 L1 1H T1 BDX53A T3 BC394 D3 1N4148 R4 270 R5 270 T4 BC393 T5 BC393 R6 20K R7 3.3K C16 1.8nF R8 3.3K C17 1.8nF Z2 3.9V Z1 3.9V L2 1H R19 270 D4 1N4148 D2 BYW98100 R1 2 R2 2 C9 330nF C10 330nF T2 BDX54A T6 BC393 T7 BC394 T8 BC394 R9 270 R10 270 R11 20K OUT INC7 100nF C5 1000F 35V C8 100nF C6 1000F 35V C1 1000F 63V C2 1000F 63V C3 100nF C4 100nF +50V +25V D1 BYW98100 GND -25V -50V D97AU807C 12 D6 1N4001 R20 20K R21 20K D7 1N4001 R22 10K R23 10K Pot Figure 6: High Efficiency ApplicationCircuit Figure 6a: PCBand ComponentLayout of the fig. 6 TDA7294S 9/13 IN-2 R2 680 C2 22F C1 470nF IN+ R1 22K 3 R3 22K - + MUTE STBY 4 10 9 SGND MUTE STBY R4 22K THERMAL SHUTDOWN S/C PROTECTION R5 10K C3 10F C4 10F 1 STBY-GND C5 47F 713 14 6 158 -Vs-PWVs BOOTSTRAP OUT +PWVs+Vs C9 100nFC8 1000F -Vs D97AU808C +Vs C7 100nFC6 1000F BUFFER DRIVER 11 BOOT LOADER 12 IN-2 IN+3 - + MUTE STBY 4 10 9 SGND MUTE THERMAL SHUTDOWN S/C PROTECTION 1 STBY-GND 713 14 6 158 -Vs-PWVs BOOTSTRAP OUT +PWVs+Vs C9 100nFC8 1000F -Vs +Vs C7 100nFC6 1000F BUFFER DRIVER 11 BOOT LOADER 12 5 CLIP DET 5 MASTER SLAVE C10 100nF R7 2 VMUTE VSTBY STBY Figure 7: Mo