TDA7296S 70V - 60W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY VERY HIGH OPERATING VOLTAGE RANGE (35V) DMOS POWER STAGE HIGH OUTPUT POWER (THD = 10%, UP TO 60W) MUTING/STAND-BY FUNCTIONS NO SWITCH ON/OFF NOISE VERY LOW DISTORTION VERY LOW NOISE SHORT CIRCUIT PROTECTION THERMAL SHUTDOWN CLIP DETECTOR MODULARITY (MORE DEVICES CAN BE EASILY CONNECTED IN PARALLEL TO DRIVE VERY LOW IMPEDANCES) MULTIPOWER BCD TECHNOLOGY Multiwatt15 ORDERING NUMBER: TDA7296SV class TV). Thanks to the wide voltage range and to the high out current capability it is able to supply the highest power into 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 optimizing the thermal dissipation of the system. DESCRIPTION The TDA7296S 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, TopFigure 1: Typical Application and Test Circuit +Vs C7 100nF C6 1000F R3 22K C1 470nF BUFFER DRIVER +Vs C2 R2 22F 680 IN- 2 IN+ 3 7 +PWVs 11 13 - R5 10K MUTE STBY BOOT LOADER C5 22F 6 10 5 THERMAL SHUTDOWN MUTE VSTBY 12 4 (**) VMUTE OUT + R1 22K SGND 14 9 S/C PROTECTION (*) BOOTSTRAP CLIP DET VCLIP STBY R4 22K C3 10F C4 10F (*) see Application note (**) for SLAVE function July 2000 1 8 15 STBY-GND -Vs -PWVs C9 100nF C8 1000F -Vs D97AU805A 1/11 TDA7296S PIN CONNECTION (Top view) 15 -VS (POWER) 14 OUT 13 +VS (POWER) 12 BOOTSTRAP LOADER 11 BUFFER DRIVER 10 MUTE 9 STAND-BY 8 -VS (SIGNAL) 7 +VS (SIGNAL) 6 BOOTSTRAP 5 CLIP AND SHORT CIRCUIT DETECTOR 4 SIGNAL GROUND 3 NON INVERTING INPUT 2 INVERTING INPUT 1 STAND-BY GND TAB CONNECTED TO PIN 8 D97AU806 QUICK REFERENCE DATA Symbol VS GLOOP Ptot SVR Parameter Test Conditions Min. Typ. Max. Unit Supply Voltage Operating 12 35 V Closed Loop Gain 26 45 dB Output Power VS = 30V; RL = 8; THD = 10% 60 VS = 25V; RL = 4; THD = 10% 60 W 75 dB Supply Voltage Rejection W ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit 35 60 V Input Voltage (inverting) Referred to -VS 60 V Maximum Differential Inputs 30 V V3 Input Voltage (non inverting) Referred to -VS 60 V V4 Signal GND Voltage Referred to -VS 60 V V5 Clip Detector Voltage Referred to -VS 60 V V6 Bootstrap Voltage Referred to -VS 60 V VS Supply Voltage (No Signal) V1 VSTAND-BY GND Voltage Referred to -VS (pin 8) V2 V2 - V3 V V9 Stand-by Voltage Referred to -VS 60 V V10 Mute Voltage Referred to -VS 60 V V11 Buffer Voltage Referred to -VS 60 V V12 Bootstrap Loader Voltage Referred to -VS 60 V Output Peak Current 10 A Ptot Power Dissipation T case = 70C 50 W Top Operating Ambient Temperature Range 0 to 70 C 150 C IO Tstg, Tj Storage and Junction Temperature THERMAL DATA Symbol Rth j-case 2/11 Description Thermal Resistance Junction-case Typ Max Unit 1 1.5 C/W TDA7296S ELECTRICAL CHARACTERISTICS (Refer to the Test Circuit VS = 24V, RL = 8, GV = 30dB; Rg = 50 ; Tamb = 25C, f = 1 kHz; unless otherwise specified). Symbol Parameter Test Condition Min. VS Operating Supply Range 10 Iq Quiescent Current 20 Ib Typ. 30 Max. Unit 35 V 60 mA Input Bias Current 500 nA VOS Input Offset Voltage 10 mV IOS Input Offset Current 100 nA PO RMS Continuous Output Power d d = 0.5%: VS = 24V, R L = 8 VS = 21V, R L = 6 VS = 18V, R L = 4 Music Power (RMS) (*) t = 1s d = 10%; R L = 8 ; VS = 30V R L = 6 ; VS = 24V R L = 4; VS = 23V Total Harmonic Distortion (**) PO = 5W; f = 1kHz PO = 0.1 to 20W; f = 20Hz to 20kHz 27 27 27 Slew Rate GV Open Loop Voltage Gain GV Closed Loop Voltage Gain eN Total Input Noise fL, fH Ri SVR TS Frequency Response (-3dB) Supply Voltage Rejection 60 60 60 W W W 0.1 % % 0.1 % % 0.01 7 26 A = curve f = 20Hz to 20kHz 10 V/s 80 dB 30 1 2 PO = 1W Input Resistance W W W 0.005 VS = 18V, RL = 4: PO = 5W; f = 1kHz PO = 0.1 to 20W; f = 20Hz to 20kHz SR 30 30 30 45 dB 5 V V 20Hz to 20kHz 100 f = 100Hz; Vripple = 0.5Vrms 60 Thermal Shutdown k 75 dB 150 C STAND-BY FUNCTION (Ref: -V S or GND) VST on Stand-by on Threshold VST off Stand-by off Threshold 3.5 Stand-by Attenuation 70 ATTst-by Iq st-by 1.5 Quiescent Current @ Stand-by V V 90 1 dB 3 mA 1.5 V MUTE FUNCTION (Ref: -VS or GND) VMon Mute on Threshold VMoff Mute off Threshold 3.5 Mute Attenuation 60 ATTmute V 80 dB Note (**): MUSIC 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 1KHz. Note (**): Tested with optimized Application Board (see fig. 2) 3/11 TDA7296S Figure 2: Typical Application P.C. Board and Component Layout (scale 1:1) 4/11 TDA7296S APPLICATION 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 Figure 1. Different values can be used; the following table can help the designer. LARGER THAN SUGGESTED SMALLER THAN SUGGESTED INCREASE INPUT IMPEDANCE DECREASE INPUT IMPEDANCE COMPONENTS SUGGESTED VALUE PURPOSE R1 (*) 22k INPUT RESISTANCE R2 680 R3 (*) 22k R4 22k ST-BY TIME CONSTANT LARGER ST-BY ON/OFF TIME SMALLER ST-BY ON/OFF TIME; POP NOISE R5 10k MUTE TIME CONSTANT LARGER MUTE ON/OFF TIME SMALLER MUTE ON/OFF TIME C1 0.47F INPUT DC DECOUPLING HIGHER LOW FREQUENCY CUTOFF C2 22F FEEDBACK DC DECOUPLING HIGHER LOW FREQUENCY CUTOFF C3 10F MUTE TIME CONSTANT LARGER MUTE ON/OFF TIME SMALLER MUTE ON/OFF TIME C4 10F ST-BY TIME CONSTANT LARGER ST-BY ON/OFF TIME SMALLER ST-BY ON/OFF TIME; POP NOISE C5 22FXN (***) BOOTSTRAPPING C6, C8 1000F SUPPLY VOLTAGE BYPASS C7, C9 0.1F SUPPLY VOLTAGE BYPASS CLOSED LOOP GAIN DECREASE OF GAIN INCREASE OF GAIN SET TO 30dB (**) INCREASE OF GAIN DECREASE OF GAIN SIGNAL DEGRADATION AT LOW FREQUENCY DANGER OF OSCILLATION (*) R1 = R3 for pop optimization (**) Closed Loop Gain has to be 26dB (***) Multiply this value for the number of modular part connected Slave function: pin 4 (Ref to pin 8 -VS) -VS +3V -VS +1V -VS MASTER UNDEFINED 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 Boucherot Cell, in order to avoid dangerous spurious oscillations when the speakers terminal are shorted. The suggested Boucherot Resistor is 3.9/2W and the capacitor is 1F. SLAVE D98AU821 5/11 TDA7296S INTRODUCTION In consumer electronics, an increasing demand has arisen for very high power monolithic audio amplifiers able to match, with a low cost, the performance obtained from the best discrete designs. The task of realizing this linear integrated circuit in conventional bipolar technology is made extremely difficult by the occurence of 2nd breakdown phoenomenon. It limits the safe operating area (SOA) of the power devices, and, as a consequence, the maximum attainable output 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 protection circuits. To overcome these substantial drawbacks, the use of power MOS devices, which are immune from secondary breakdown is highly desirable. 1) Output Stage The main design task in developping a power operational amplifier, independently of the technology used, is that of realization of the output stage. The solution shown as a principle shematic by Fig3 represents the DMOS unity - gain output buffer of the TDA7296S. This large-signal, high-power buffer must be capable of handling extremely high current and voltage levels while maintaining acceptably low harmonic distortion and good behaviour over frequency response; moreover, an accurate control of quiescent current is required. A local linearizing feedback, provided by differential amplifier A, is used to fullfil the above requirements, allowing a simple and effective quiescent current setting. Proper biasing of the power output transistors alone is however not enough to guarantee the absence of crossover distortion. While a linearization of the DC transfer characteristic of the stage is obtained, the dynamic behaviour of the system must be taken into account. A significant aid in keeping the distortion contributed by the final stage as low as possible is provided by the compensation scheme, which exploits the direct connection of the Miller capacitor at the amplifier's output to introduce a local AC feedback path 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 conditions. Due to the absence of the 2nd breakdown phenomenon, the SOA of the power DMOS transistors 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 implemented in this device combines a conventional SOA protection circuit with a novel local temperature sensing technique which " dynamically" controls the maximum dissipation. In addition to the overload protection described Figure 3: Principle Schematic of a DMOS unity-gain buffer. 6/11 TDA7296S Figure 4: Turn ON/OFF Suggested Sequence +Vs (V) +40 -40 -Vs VIN (mV) VST-BY PIN #9 (V) 5V 5V VMUTE PIN #10 (V) IQ (mA) VOUT (V) OFF ST-BY PLAY MUTE ST-BY OFF MUTE D98AU817 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 pin is included. Figure 5: Single Signal ST-BY/MUTE Control Circuit avoid any kind of uncontrolled audible transient at the output. The sequence that we recommend during the ON/OFF transients 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 applicable range corresponds to the operating supply voltage. APPLICATION INFORMATION MUTE STBY 20K MUTE/ ST-BY 10K 30K 1N4148 10F 10F D93AU014 3) Other Features The device is provided with both stand-by and mute functions, independently driven by two CMOS logic compatible input pins. The circuits dedicated to the switching on and off of the amplifier have been carefully optimized to BRIDGE APPLICATION Another application suggestion is the BRIDGE configuration, where two TDA7296S are used. In this application, the value of the load must not be lower than 8 Ohm for dissipation and current capability reasons. A suitable field of application includes HI-FI/TV subwoofers realizations. The main advantages offered by this solution are: - High power performances with limited supply voltage level. - Considerably high output power even with high load values (i.e. 16 Ohm). With Rl= 8 Ohm, Vs = 23V the maximum output power obtainable is 120W (Music Power) 7/11 TDA7296S The slave SGND pin must be tied to the negative supply. The slave ST-BY pin must be connected to ST-BY pin. The bootstrap lines must be connected together and the bootstrap capacitor must be increased: for N devices the boostrap capacitor must be 22F times N. The slave Mute and IN-pins must be grounded. 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 together. THE BOOTSTRAP CAPACITOR For compatibility purpose with the previous devices of the family, the boostrap capacitor can be connected both between the bootstrap pin (6) and the output pin (14) or between the boostrap pin (6) and the bootstrap loader pin (12). The master chip connections are the same as the normal single ones. The outputs can be connected together without the need of any ballast resistance. Figure 6: Modular Application Circuit +Vs C7 100nF C6 1000F R3 22K MASTER BUFFER DRIVER +Vs C2 22F R2 680 C1 470nF IN- 2 IN+ 3 +PWVs 11 7 13 - VMUTE R5 10K 4 MUTE 10 STBY 9 R4 22K C4 10F 12 BOOT LOADER 6 MUTE VSTBY OUT + R1 22K SGND 14 THERMAL SHUTDOWN STBY S/C PROTECTION 1 8 15 STBY-GND -Vs -PWVs C9 100nF C3 10F 5 C10 100nF R7 2 C5 47F BOOTSTRAP CLIP DET C8 1000F -Vs +Vs C7 100nF C6 1000F BUFFER DRIVER +Vs IN- 2 IN+ 3 +PWVs 11 7 13 - 4 MUTE 10 9 STBY 12 BOOT LOADER 6 MUTE THERMAL SHUTDOWN STBY S/C PROTECTION 1 8 15 STBY-GND -Vs -PWVs C9 100nF C8 1000F -Vs 8/11 OUT + SLAVE SGND 14 5 BOOTSTRAP D97AU808C TDA7296S Figure 7a: Modular Application P.C. Board and Component Layout (scale 1:1) (Component SIDE) Figure 7b: Modular Application P.C. Board and Component Layout (scale 1:1) (Solder SIDE) 9/11 TDA7296S DIM. mm MIN. TYP. A B C inch MAX. MIN. TYP. 5 2.65 1.6 MAX. 0.197 0.104 0.063 D E 0.49 0.55 0.019 0.022 F 0.66 0.75 0.026 0.030 G G1 1.02 17.53 H1 H2 19.6 L L1 21.9 21.7 L2 L3 L4 17.65 17.25 10.3 L7 2.65 M M1 4.25 4.63 S S1 Dia1 10/11 1 1.27 17.78 OUTLINE AND MECHANICAL DATA 0.039 1.52 0.040 18.03 0.690 0.050 0.700 0.060 0.710 0.772 20.2 0.795 22.2 22.1 22.5 22.5 0.862 0.854 17.5 10.7 18.1 17.75 10.9 0.695 0.679 0.406 2.9 0.104 4.85 5.53 0.167 0.182 1.9 1.9 2.6 2.6 0.075 0.075 0.102 0.102 3.65 3.85 0.144 0.152 4.55 5.08 0.874 0.870 0.886 0.886 0.689 0.421 0.713 0.699 0.429 0.114 0.179 0.200 0.191 0.218 Multiwatt15 V TDA7296S Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics 2000 STMicroelectronics - Printed in Italy - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. http://www.st.com 11/11