100V - 100W DMOS audio amplifier with mute/st-by

1 TDA7294100V - 100W DMOS audio amplifier WITH mute /ST-BYVERY HIGH OPERATING VOLTAGE RANGE( 40V)DMOS POWER STAGEHIGH OUTPUT POWER (UP TO 100W MU-SIC POWER)MUTING/STAND-BY FUNCTIONSNO SWITCH ON/OFF NOISENO BOUCHEROT CELLSVERY LOW DISTORTIONVERY LOW NOISESHORT CIRCUIT PROTECTIONTHERMAL SHUTDOWNDESCRIPTIONThe TDA7294 is a monolithic integrated circuit inMultiwatt15 package, intended for use as audioclass AB amplifier in Hi-Fi field applications(Home Stereo, self powered loudspeakers, Top-class TV). Thanks to the wide voltage range andto the high out current capability it is able to sup-ply the highest power into both 4 and 8 loadseven in presence of poor supply regulation, withhigh Supply Voltage built in muting function with turn on delaysimplifies the remote operation avoiding switchingon-off 2003 IN-2R2680 C222 FC1 470nFIN+R1 C10100nF3R3 22K-+MUTESTBY4 VMVSTBY109IN+MUTEMUTESTBYR4 22 KTHERMALSHUTDOWNS/CPROTECTIONR5 10KC3 10 FC4 10 F1 STBY-GNDC522 F713146158-Vs-PWVsBOOT-STRAPOUT+PWVs+VsC 9 100nFC8 1000 F-VsD93AU011+VsC7 100nFC6 1000 FNote: The Boucherot cell R6, C10, normally not necessary for a stable operation it could be needed in presence of particular load impedances at VS < 1.

2 Typical Application and Test CircuitMULTIPOWER BCD TECHNOLOGYM ultiwatt15V Multiwatt15 HORDERING NUMBERS: TDA7294V TDA7294HS1/17 BLOCK DIAGRAMABSOLUTE MAXIMUM RATINGSS ymbolParameterValueUnitVSSupply Voltage (No Signal) 50 VIOO utput Peak Current10 APtotPower Dissipation Tcase = 70 C50 WTopOperating Ambient Temperature Range0 to 70 CTstg, TjStorage and Junction Temperature150 CTAB connected to -VSPIN CONNECTION (Top view)TDA72942/17 THERMAL DATAS ymbolDescriptionValueUnitRth j-caseThermal Resistance C/WELECTRICAL CHARACTERISTICS (Refer to the Test Circuit VS = 35V, RL = 8 , GV = 30dB; Rg = 50 ; Tamb = 25 C, f = 1 kHz; unless otherwise Range 10 40 VIqQuiescent Current203065mAIbInput Bias Current500nAVOSI nput Offset Voltage+10mVIOSI nput Offset Current+100nAPORMS Continuous Output Powerd = :VS = 35V, RL = 8 VS = 31V, RL = 6 VS = 27V, RL = 4 606060707070 WWWM usic Power (RMS) RULES - t = 1s (*)d = 10% RL = 8 ; VS = 38 VRL = 6 ; VS = 33 VRL = 4 ; VS = 29V (**)100100100 WWWdTotal Harmonic Distortion (**)PO = 5W; f = 1kHzPO = to 50W; f = 20Hz to = 27V, RL = 4 :PO = 5W; f = 1kHzPO = to 50W; f = 20Hz to Rate710V/ sGVOpen Loop Voltage Gain80dBGVC losed Loop Voltage Gain243040dBeNTotal Input NoiseA = curvef = 20Hz to 20kHz125 V VfL, fHFrequency Response (-3dB)PO = 1W20Hz to 20kHzRiInput Resistance 100k SVRS upply Voltage Rejectionf = 100Hz.)

3 Vripple = Shutdown145 CSTAND-BY FUNCTION (Ref: -VS or GND)VST onStand-by on offStand-by off Attenuation7090dBIq st-byQuiescent Current @ Stand-by13mAMUTE FUNCTION (Ref: -VS or GND)VMonMute on off AttenuatIon6080dBNote (*):MUSIC POWER CONCEPTMUSIC POWER is the maximal power which the amplifier is capable of producing across the rated load resistance (regardless of non linearity)1 sec after the application of a sinusoidal input signal of frequency (**): Tested with optimized Application Board (see fig. 2)Note (**): Limited by the max. allowable 2: and components layout of the circuit of figure 1. (1:1 scale)Note:The Stand-by and mute functions can be referred either to GND or the is possible to set both the configuration through the jumper SUGGESTIONS (see Test and Application Circuits of the Fig. 1)The recommended values of the external components are those shown on the application circuit of Fig-ure 1.

4 Different values can be used; the following table can help the VALUEPURPOSELARGER THANSUGGESTEDSMALLER THANSUGGESTEDR1 (*)22kINPUT RESISTANCEINCREASE INPUTIMPRDANCEDECREASE INPUTIMPEDANCER2680 CLOSED LOOP GAINSET TO 30dB (**)DECREASE OF GAIN INCREASE OF GAINR3 (*)22kINCREASE OF GAIN DECREASE OF GAINR422kST-BY TIMECONSTANTLARGER ST-BYON/OFF TIMESMALLER ST-BYON/OFF TIME;POP NOISER510kMUTE TIMECONSTANTLARGER MUTEON/OFF TIMESMALLER MUTEON/OFF FINPUT DCDECOUPLINGHIGHER LOWFREQUENCYCUTOFFC222 FFEEDBACK DCDECOUPLINGHIGHER LOWFREQUENCYCUTOFFC310 FMUTE TIMECONSTANTLARGER MUTEON/OFF TIMESMALLER MUTEON/OFF TIMEC410 FST-BY TIMECONSTANTLARGER ST-BYON/OFF TIMESMALLER ST-BYON/OFF TIME;POP NOISEC522 FBOOTSTRAPPINGSIGNALDEGRADATION ATLOW FREQUENCYC6, C81000 FSUPPLY VOLTAGEBYPASSDANGER OFOSCILLATIONC7, FSUPPLY VOLTAGEBYPASSDANGER OFOSCILLATION(*) R1 = R3 FOR POP OPTIMIZATION(**) CLOSED LOOP GAIN HAS TO BE 24dBTDA72945/17 Figure 3: Output Power vs.

5 Supply Voltage. Figure 5: Output Power vs. Supply VoltageFigure 4: Distortion vs. Output PowerFigure 8: Distortion vs. FrequencyTYPICAL CHARACTERISTICS(Application Circuit of fig 1 unless otherwise specified)Figure 6: Distortion vs. Output PowerFigure 7: Distortion vs. FrequencyTDA72946/17 Figure 14: Power Dissipation vs. Output PowerFigure 13: Power Dissipation vs. Output PowerFigure 11: mute Attenuation vs. Vpin10 Figure 12: St-by Attenuation vs. Vpin9 Figure 10: Supply Voltage Rejection vs. FrequencyTYPICAL CHARACTERISTICS (continued)Figure 9: Quiescent Current vs. Supply VoltageTDA72947/17 INTRODUCTIONIn consumer electronics, an increasing demandhas arisen for very high power monolithic audioamplifiers able to match, with a low cost the per-formance obtained from the best discrete task of realizing this linear integrated circuitin conventional bipolar technology is made ex-tremely difficult by the occurence of 2nd break-down phenomenon.

6 It limits the safe operatingarea (SOA) of the power devices, and as a con-sequence, the maximum attainable output power,especially in presence of highly reactive , full exploitation of the SOA translatesinto a substantial increase in circuit and layoutcomplexity due to the need for sophisticated pro-tection overcome these substantial drawbacks, theuse of power MOS devices, which are immunefrom secondary breakdown is highly desirable. The device described has therefore been devel-oped in a mixed bipolar-MOS high voltage tech-nology called BCD ) Output StageThe main design task one is confronted with whiledeveloping an integrated circuit as a power op-erational amplifier , independently of the technol-ogy used, is that of realizing the output solution shown as a principle shematic by Fig15 represents the DMOS unity-gain output bufferof the 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.

7 Moreover, an accurate controlof quiescent current is local linearizing feedback, provided by differen-tial amplifier A, is used to fullfil the above require-ments, allowing a simple and effective quiescentcurrent biasing of the power output transistorsalone is however not enough to guarantee the ab-sence of crossover a linearization of the DC transfer charac-teristic of the stage is obtained, the dynamic be-haviour of the system must be taken into 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 capacitorat the amplifier s output to introduce a local ACfeedback path enclosing the output stage ) ProtectionsIn designing a power IC, particular attention mustbe reserved to the circuits devoted to protectionof the device from short circuit or overload condi-tions.

8 Due to the absence of the 2nd breakdown phe-nomenon, the SOA of the power DMOS transis-tors is delimited only by a maximum dissipationcurve dependent on the duration of the order to fully exploit the capabilities of thepower transistors, the protection scheme imple-mented in this device combines a conventionalSOA protection circuit with a novel local tempera-ture sensing technique which " dynamically" con-trols the maximum 15: Principle Schematic of a DMOS unity-gain addition to the overload protection describedabove, the device features a thermal shutdowncircuit which initially puts the device into a mutingstate (@ Tj = 145 oC) and then into stand-by (@Tj = 150 oC).Full protection against electrostatic discharges onevery pin is ) Other Features The device is provided with both stand-by andmute functions, independently driven by twoCMOS logic compatible input pins.

9 The circuits dedicated to the switching on and offof the amplifier have been carefully optimized toavoid any kind of uncontrolled audible transient atthe sequence that we recommend during theON/OFF transients is shown by Figure application of figure 17 shows the possibilityof using only one command for both st-by andmute functions. On both the pins, the maximumapplicable range corresponds to the operatingsupply F10 FMUTESTBYD93AU014 mute /ST-BYFigure 17: Single Signal ST-BY/ mute ControlCircuitPLAYOFFST-BYMUTEMUTEST-BYO FFD93AU0135V5V+Vs(V)+35-35 VMUTEPIN #10(V)VST-BYPIN #9(V)-VsVIN(mV)IP(mA)VOUT(V)Figure 16: Turn ON/OFF Suggested SequenceTDA72949/17 TDA7294314137815214610R3 680C11 22 FL3 5 H270R1613KC1522 F9R1613KC13 10 FR13 20KC11 330nFR15 10KC1410 FR14 30KD51N4148 PLAYST-BY270L1 1 HT1 BDX53AT3BC394D3 1 H270D4 1N4148D2 BYW98100R12R22C9330nFC10330nFT2 BDX54AT6BC393T7BC394T8BC394R9270R10270R1 129 KOUTINC7100nFC51000 FC8100nFC61000 FC11000 FC21000 FC3100nFC4100nF+40V+20VD1 BYW98100 GND-20V-40VD93AU016 Figure 18.

10 High Efficiency Application CircuitAPPLICATION INFORMATIONHIGH-EFFICIENCYC onstraints of implementing high power solutionsare the power dissipation and the size of thepower supply. These are both due to the low effi-ciency of conventional AB class amplifier below (figure 18) is described a circuit pro-posal for a high efficiency amplifier which can beadopted for both HI-FI and CAR-RADIO TDA7294 is a monolithic MOS power ampli-fier which can be operated at 80V supply voltage(100V with no signal applied) while delivering out-put currents up to 10 allows the use of this device as a very highpower amplifier (up to 180W as peak power % and Rl = 4 Ohm); the only drawbackis the power dissipation, hardly manageable inthe above power 20 shows the power dissipation versusoutput power curve for a class AB amplifier , com-pared with a high efficiency order to dimension the heatsink (and the powersupply), a generally used average output powervalue is one tenth of the maximum output powerat %.