TDA7375A 2 X 37W DUAL/QUAD POWER AMPLIFIER FOR CAR RADIO 1 ■ ■ ■ FEATURES Figure 1. Package HIGH OUTPUT POWER CAPABILITY: – 2 x 43W max./4Ω – 2 x 37W/4Ω EIAJ – 2 x 26W/4Ω @14.4V, 1KHz, 10% – 4 x 7W/4Ω @14.4V,1KHz, 10% – 4 x 12W/2Ω @14.4V, 1KHz, 10% MINIMUM EXTERNAL COMPONENTS COUNT: – NO BOOTSTRAP CAPACITORS – NO BOUCHEROT CELLS – INTERNALLY FIXED GAIN (26dB BTL) ST-BY FUNCTION (CMOS COMPATIBLE) MULTIWATT15 Table 1. Order Codes 2 ■ ■ NO AUDIBLE POP DURING ST-BY OPERATIONS ■ DIAGNOSTICS FACILITY FOR: ■ – – – – – ■ CLIPPING OUT TO GND SHORT OUT TO VS SHORT SOFT SHORT AT TURN-ON THERMAL SHUTDOWN PROXIMITY ■ ■ ■ ■ ■ Part Number Package TDA7375AV MULTIWATT 15 (Vertical) PROTECTIONS: OUPUT AC/DC SHORT CIRCUIT – TO GND – TO VS – ACROSS THE LOAD SOFT SHORT AT TURN-ON OVERRATING CHIP TEMPERATURE WITH SOFT THERMAL LIMITER LOAD DUMP VOLTAGE SURGE VERY INDUCTIVE LOADS FORTUITOUS OPEN GND REVERSED BATTERY ESD Figure 2. Block Diagram March 2005 Rev. 2 1/15 TDA7375A 3 DESCRIPTION The TDA7375A is a new technology class AB car radio amplifier able to work either in DUAL BRIDGE or QUAD SINGLE ENDED configuration. The exclusive fully complementary structure of the output stage and the internally fixed gain guarantee the highest possible power performances with extremely reduced component count. The on-board clip detector simplifies gain compression operation. The fault diagnostics makes it possible to detect mistakes during car radio set assembly and wiring in the car. Table 2. Absolute Maximum Ratings Symbol Parameter Value Unit Vop Operating Supply Voltage 18 V VS DC Supply Voltage 28 V Peak Supply Voltage (for t = 50ms) 40 V IO Output Peak Current (not repetitive t = 100µs) 4.5 A IO Output Peak Current (repetitive f > 10Hz) 3.5 A Power Dissipation (Tcase = 85°C) 36 W -40 to 150 °C Vpeak Ptot Tstg, Tj Storage and Junction Temperature Table 3. Thermal Data Symbol Rth j-case Parameter Thermal Resistance Junction-case Figure 3. Pin Connection (Top view) 2/15 max Value Unit 1.8 °C/W TDA7375A Table 4. Electrical Characteristcs (Refer to the test circuit, VS = 14.4V; RL = 4Ω; f = 1KHz; Tamb = 25°C, unless otherwise specified) Symbol Parameter VS Supply Voltage Range Id Total Quiescent Drain Current VOS Output Offset Voltage PO Output Power Test Condition Min. Typ. 8 RL = ∞ Max. Unit 18 V 150 mA 150 mV THD = 10%; RL = 4Ω Bridge Single Ended Single Ended, RL = 2Ω 23 6.5 25 7 12 W W W PO max Max. Output Power (***) VS = 14.4V, Bridge 37 43 W PO EIAJ EIAJ Output Power (***) VS = 13.7V, Bridge 33 37 W Distortion RL = 4Ω Single Ended, PO = 0.1 to 4W Bridge, PO = 0.1 to 10W THD CT Cross Talk 0.02 0.03 f = 1KHz Single Ended 70 f = 10KHz Single Ended f = 1KHz Bridge 0.3 dB 60 dB 55 f = 10KHz Bridge % % dB 60 dB 20 30 KΩ RIN Input Impedance Single Ended Bridge 10 15 GV Voltage Gain Single Ended 19 20 21 dB Bridge 25 26 27 dB 0.5 dB GV Voltage Gain Match EIN Input Noise Voltage Rg = 0; ”A” weighted, S.E. Non Inverting Channels Inverting Channels Bridge Rg = 0; 22Hz to 22KHz SVR Supply Voltage Rejection Rg = 0; f = 300Hz 50 ASB Stand-by Attenuation PO = 1W 80 ISB ST-BY Current Consumption VST-BY = 0 to 1.5V VSB ST-BY In Threshold Voltage VSB ST-BY Out Threshold Voltage Ipin7 ST-BY Pin Current KΩ 2 5 µV µV 3.5 µV dB 90 dB 100 µA 1.5 V 3.5 V Play Mode Vpin7 = 5V 50 µA Max Driving Curr. Under Fault (*) 5 mA off Clipping Detector Output Average Current d = 1% (**) 90 µA Icd on Clipping Detector Output Average Current d = 5% (**) 160 µA Voltage Saturation on pin 10 Sink Current at Pin 10 = 1mA Icd Vsat pin10 0.7 V (*) See built-in S/C protection description (**) Pin 10 Pulled-up to 5V with 10KΩ; RL = 4Ω (***) Saturated square wave output. 3/15 TDA7375A 4 STANDARD TEST AND APPLICATION CIRCUIT Figure 4. Quad Stereo 10K R1 ST-BY C7 10µF IN FL 4 13 7 3 1 C1 0.22µF IN FR 5 12 C4 0.22µF OUT FL C9 2200µF OUT FR C11 2200µF OUT RL C12 2200µF OUT RR 15 IN RR Note: The output decoupling capacitors (C9,C10,C11,C12) could be reduced to 1000µF if the 2Ω operation is not required. C10 2200µF 2 C2 0.22µF IN RL VS C5 1000µF C6 100nF 11 C3 0.22µF 6 14 8 10 9 C8 47µF DIAGNOSTICS D94AU063A Figure 5. Double Bridge 10K R1 ST-BY C5 10µF IN L C1 0.47µF IN R 13 7 4 3 1 OUT L 5 2 12 C2 0.47µF 15 11 OUT R 6 C8 47µF VS C3 1000µF C4 100nF 14 8 10 9 DIAGNOSTICS D94AU064A Figure 6. Stereo/Bridge 10K ST-BY VS 10µF IN L 100nF 7 4 13 3 1 0.22µF IN L 2200µF 2 5 2200µF 0.22µF IN BRIDGE 8 OUT R OUT BRIDGE 11 6 OUT L 15 12 0.47µF 1000µF 9 10 14 47µF DIAGNOSTICS 4/15 D94AU065A TDA7375A Figure 7. P.C. Board and Component Layout of the fig.4 Figure 8. P.C. Board and Component Layout of the fig.5 5/15 TDA7375A Figure 9. Quiescent Drain Current vs. Supply Voltage (Single Ended and Bridge). Figure 12. Output Power vs. Supply Voltage Figure 10. Quiescent Output Voltage vs. Supply Voltage (Single Ended and Bridge). Figure 13. OutputPower vs. Supply Voltage Figure 11. Output Power vs. Supply Voltage Figure 14. Distortion vs. Output Power 6/15 TDA7375A Figure 15. Distortion vs. Output Power Figure 18. Supply Voltage Rejection vs. Frequency Figure 16. Distortion vs. Output Power Figure 19. Supply Voltage Rejection vs. Frequency Figure 17. Cross-talk vs. Frequency Figure 20. Stand-by Attenuation vs. Threshold Voltage 7/15 TDA7375A Figure 21. Total Power Dissipation and Efficiency vs. Output Power 5 Figure 22. Total Power Dissipation and Efficiency vs. Output Power GENERAL STRUCTURE 5.1 High Application Flexibility The availability of 4 independent channels makes it possible to accomplish several kinds of applications ranging from 4 speakers stereo (F/R) to 2 speakers bridge solutions. In case of working in single ended conditions the polarity of the speakers driven by the inverting amplifier must be reversed respect to those driven by non inverting channels. This is to avoid phase inconveniences causing sound alterations especially during the reproduction of low frequencies. 5.2 Easy Single Ended to Bridge Transition The change from single ended to bridge configurations is made simply by means of a short circuit across the inputs, that is no need of further external components. 5.3 Gain Internally Fixed to 20dB in Single Ended, 26dB in Bridge Advantages of this design choice are in terms of: ■ componentsand space saving ■ output noise, supply voltage rejection and distortion optimization. 5.4 Silent Turn On/Off and Muting/Stand-by Function The stand-by can be easily activated by means of a CMOS level applied to pin 7 through a RC filter. Under stand-by condition the device is turned off completely (supply current = 1µA typ.; output attenuation = 80dB min.). Every ON/OFF operation is virtually pop free. Furthemore, at turn-on the device stays in muting condition for a time determined by the value assigned to the SVR capacitor. While in muting the device outputs becomes insensitive to any kinds of signal that may be present at the input terminals. In other words every transient coming from previous stages produces no unplesantacoustic effect to the speakers. 5.5 OUTPUT STAGE The fully complementary output stage was made possible by the development of a new component: the 8/15 TDA7375A ST exclusive power ICV PNP. A novel design based upon the connection shown in fig. 23 has then allowed the full exploitation of its possibilities. The clear advantagesthis new approach has over classical output stages are as follows: 5.5.1 Rail-to-Rail Output Voltage Swing With No Need of Bootstrap Capacitors. The output swing is limited only by the VCEsat of the output transistors, which is in the range of 0.3Ω (Rsat) each. Classical solutions adopting composite PNP-NPN for the upper output stage have higher saturation loss on the top side of the waveform. This unbalanced saturation causes a significant power reduction. The only way to recover power consists of the addition of expensive bootstrap capacitors. 5.5.2 Absolute Stability Without Any External Compensation. Referring to the circuit of fig. 23 the gain VOut/VIn is greater than unity, approximately 1+R2/R1. The DC output (VCC/2) is fixed by an auxiliary amplifier common to all the channels. By controlling the amount of this local feedbackit is possible to force the loop gain (A*β) to less than unity at frequency for which the phase shift is 180°. This means that the output buffer is intrinsically stableand not prone to oscillation. Most remarkably, the above feature has been achieved in spite of the very low closed loop gain of the amplifier. In contrast, with the classical PNP-NPN stage, the solution adopted for reducing the gain at high frequencies makes use of external RC networks, namely the Boucherot cells. 5.6 BUILT–IN SHORTCIRCUIT PROTECTION Figure 23. The New Output Stage Reliable and safe operation, in presence of all kinds of short circuit involving the outputs is assured by BUILT-IN protectors. Additionally to the AC/DC short circuit to GND, to VS, across the speaker, a SOFT SHORT condition is signalled out during the TURN-ON PHASE so assuring correct operation for the device itself and for the loudspeaker. This particular kind of protection acts in a way to avoid that the device is turned on (by ST-BY) when a resistive path (less than 16 ohms) is present between the output and GND. As the involved circuitry is normally disabled when a current higher than 5mA is flowing into the ST-BY pin, it is important, in order not to disable it, to have the external current source driving the ST-BY pin limited to 5mA. This extrafunction becomes particularly attractive when, in the single ended configuration, one capacitor is shared between two outputs (see fig. 24). Supposing that the output capacitor Cout for anyreason is shorted, the loudspeaker will not be damaged being this soft short circuit condition revealed. 9/15 TDA7375A Figure 24. 5.6.1 Diagnostics Facility The TDA7375A is equipped with a diagnostic circuitry able to detect the following events: ■ Clipping in the output signal ■ Thermal shutdown ■ Output fault: – short to GND – short to VS – soft short at turn on The information is available across an open collector output (pin 10) through a current sinking when the event is detected A current sinking at pin 10 is triggered when a certain distortion level is reached at any of the outputs. This function allows gain compression possibility whenever the amplifier is overdriven. 5.6.2 Thermal Shutdown In this case the output 10 will signal the proximity of the junction temperature to the shutdown threshold. Typically current sinking at pin 10 will start ~10°C before the shutdown threshold is reached. Figure 25. Clipping Detection Waveforms 10/15 TDA7375A Figure 26. Output Fault Waveforms (see fig. 27) Figure 27. Fault Waveforms 5.7 HANDLING OF THE DIAGNOSTICS INFORMATION As various kinds of information is available at the same pin (clipping detection, output fault, thermal proximity), this signal must be handled properly in order to discriminate each event. This could be done by taking into account the different timing of the diagnostic output during each case. Normally the clip detector signalling produces a low level at pin 10 that is shorter referred to everyt kind of fault detection; based on this assumption an interface circuitry to differentiate the information 11/15 TDA7375A is representedin the following schematic.Waveforms Figure 28. 12/15 TDA7375A Figure 29. Multiwatt 15 Mechanical Data & Package Dimensions DIM. mm MIN. TYP. inch MAX. MIN. TYP. A5 MAX. 0.197 B 2.65 C 0.104 1.6 D OUTLINE AND MECHANICAL DATA 0.063 1 0.039 E 0.49 0.55 0.019 0.022 F 0.66 0.75 0.026 0.030 G 1.02 1.27 1.52 0.040 0.050 0.060 G1 17.53 17.78 18.03 0.690 0.700 0.710 H1 19.6 0.772 H2 20.2 0.795 L 21.9 22.2 22.5 0.862 0.874 0.886 L1 21.7 22.1 22.5 0.854 0.87 0.886 L2 17.65 18.1 0.695 L3 17.25 17.5 17.75 0.679 0.689 L4 10.3 10.7 10.9 0.406 0.421 L7 2.65 2.9 0.104 M 4.25 4.55 4.85 0.167 0.179 M1 4.73 5.08 5.43 0.186 0.200 S 1.9 2.6 0.075 0.102 S1 1.9 2.6 0.075 0.102 Dia1 3.65 3.85 0.144 0.152 0.713 0.699 0.429 0.114 0.191 0.214 Multiwatt15 (Vertical) 0016036 J 13/15 TDA7375A 6 REVISION HISTORY Table 5. Revision History 14/15 Date Revision Description of Changes July 2004 1 First Issue in EDOCS March 2005 2 Changed the Style-sheet in compliance to the new “Corporate Technical Pubblications Design Guide”. Deleted package Mukltiwatt15 Horizontal TDA7375A 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. Specifications 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. 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