TDA1908 8W AUDIO AMPLIFIER DESCRIPTION The TDA1908 is a monolithic integrated circuit in 12 lead quad in-line plastic package intended for low frequency power applications. The mounting is compatible with the old types TBA800, TBA810S, TCA830S and TCA940N. Its main features are: – flexibility in use with a max output curent of 3A and an operating supply voltage range of 4V to 30V; – protection against chip overtemperature; – soft limiting in saturation conditions; – low ”switch-on” noise; – low number of external components; – high supply voltage rejection; – very low noise. Findip ORDERING NUMBER : TDA1908 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit Vs Supply voltage 30 V Io Output peak current (non repetitive) 3.5 A Io Output peak current (repetitive) 3 A Ptot Power dissipation: at Tamb = 80°C 1 W 5 W Tstg, Tj Storage and junction temperature -40 to 150 °C at Tamb = 90°C APPLICATION CIRCUIT March 1993 1/12 TDA1908 PIN CONNECTION (top view) SCHEMATIC DIAGRAM 2/12 TDA1908 TEST CIRCUIT * See fig. 12 THERMAL DATA Symbol Parameter Value Unit Rth j-tab Thermal resistance junction-tab max 12 °C/W Rth j-amb Thermal resistance junction-ambient max (°) 70 °C/W (°) Obtained with tabs soltered to printed circuit board with min copper area. ELECTRICAL CHARACTERISTICS (Refer to the test circuit, Tamb = 25 °C, Rth (heatsink)= 8 °C/W, unless otherwise specified) Symbol Parameter Vs Supply voltage Vo Quiescent output voltage Id VCEsat Po Quiescent drain current Output stage saturation voltage (each output transistor) Output power Test conditions Min. Typ. Max. Unit 30 V 2.1 9.2 15.5 2.5 10.2 16.8 V Vs = 4V Vs = 18V Vs = 30V 15 17.5 21 35 IC = 1A 0.5 IC = 2.5A 1.3 4 1.6 8.2 14.4 Vs = 4V Vs = 18V Vs = 30V mA V d = 10% Vs Vs Vs Vs Vs f = 1KHz = 9V RL = 4Ω = 14V RL = 4Ω = 18V RL = 4Ω = 22V RL = 8Ω = 24V RL = 16Ω 7 6.5 4.5 2.5 5.5 9 8 5.3 W 3/12 TDA1908 ELECTRICAL CHARACTERISTICS (continued) Symbol d Vi Vi Parameter Test conditions f = 1KHz Vs = 9V R L = 4Ω Po = 50 mW to 1.5 W Vs = 18V R L = 4Ω Po = 50 mW to 4W Vs = 24V R L = 16Ω Po = 50 mW to 3W Harmonic distorsion Input sensivity Input saturation voltage (rms) RL RL RL RL RL = 4Ω = 4Ω = 4Ω = 8Ω = 16Ω 60 f = 1 KHz Vs = 14V Vs = 18V Vs = 22V Vs = 24V RL RL RL RL = 4Ω = 4Ω = 8Ω = 16Ω Small signal bandwitdth (-3 dB) Vs = 18V Gv Voltage gain (open loop) f = 1 KHz Gv Voltage gain (closed loop) Vs = 18V f = 1 KHz RL = 4Ω Po = 1W eN Total input noise (°) (°°) Tsd Vs = 18V Po = 9W RL = 4Ω Signal to noise ratio (*) Note : (°) Weighting filter = curve A. (° °) Filter with noise bandwidth: 22 Hz to 22 KHz. 4/12 RL = 4Ω 5.5W 9W 8W 5.3W mV V 100 KΩ 570 730 500 310 mA % 72 Po = 1W 39.5 40 to 40 000 Hz 75 dB 40 40.5 Rg = 50Ω Rg = 1KΩ Rg = 10KΩ 1.2 1.3 1.5 4.0 Rg = 50Ω Rg = 1KΩ Rg = 10KΩ 2.0 2.0 2.2 6.0 dB µV µV Rg = 10KΩ Rg = 0 (°) 92 94 dB Rg = 10KΩ Rg = 0 (°°) 88 90 dB 50 dB 145 ÉC RL = 4Ω Vs = 18V fripple = 100 Hz Rg = 10KΩ Supply voltage rejection Termal shut-down junction temperature Po = Po = Po = Po = 2.5W 5.5W 9W 8W 5.3W Vs = 18V f = 1 KHz RL = 4Ω Po = 9W Efficiency BW SVR 37 52 64 90 110 0.8 1.3 1.8 2.4 Drain current S/N 0.1 = 9V = 14V = 18V = 24V Is Unit % Vs Vs Vs Vs f = 1 KHz Max. 0.1 = 9V = 14V = 18V = 22V = 24V Input resistence (pin 8) Po = Po = Po = Po = Po = Typ. 0.1 Vs Vs Vs Vs Vs Ri η Min. 40 TDA1908 Figure 1. Quiescent output voltage vs. supply voltage Figure 2. Quiescent drain current vs. supply voltage Figure 3. Output power vs. supply voltage Fi gur e 4 . Di stor tion v s. output power (RL = 16Ω) Fi gur e 5 . Disto rtion vs . output power (RL = 8Ω) Fi gur e 6 . Disto rtion vs . output power (RL = 4Ω) Fi g ure 7. Distortion v s. frequency (RL = 16Ω) Fi gur e 8 . Disto rtion vs . frequency (RL = 8Ω) Fi gur e 9 . Disto rtion vs . frequency (RL = 4Ω) 5/12 TDA1908 F i gu r e 1 0. Op en loo p frequency response Figure 11. Output power vs. input voltage Figure 12. Values of capacitor CX versus gain and BW Figure 13. Supply voltage rejection vs. voltage gain Figure 14. Supply voltage rej e c ti on v s . so urc e resistance Fi g ur e 1 5 . Max p owe r di s si pa ti on v s. sup ply voltage Figure 16. Power dissipation and efficiency vs. output power (Vs = 14V) Figure 17. Power dissipation and efficiencyvs. output power (Vs = 18V) Figure 18. Power dissipation and efficiency vs. output power (Vs = 24V) 6/12 TDA1908 APPLICATION INFORMATION Figure 19. Application circuit with bootstrap * R4 is necessary when Vs is less than 10V. Figure 20. P.C. board and component lay-out of the circuit of fig. 19 (1 : 1 scale) 7/12 TDA1908 APPLICATION INFORMATION (continued) Figure 21. Application circuit without bootstrap Figure 23. Position control for car headlights 8/12 Figure 22. Output power vs. supply voltage (circuit of fig. 21) TDA1908 APPLICATION SUGGESTION The recommended values of the external components are those shown on the application circuit of fig. 19. When the supply voltage Vs is less than 10V, a 100Ω resistor must be connected between pin 1 and pin 4 in order to obtain the maximum output power. Different values can be used. The following table can help the designer. Component Raccom. value Purpose Larger than raccomanded value Smaller than raccomanded value Allowed range Min. Max. 9 R2 R1 10 KΩ Close loop gain setting Increase of gain. Decrease of gain. Increase quiescent current. R2 100 Ω Close loop gain setting. Decrease of gain. Increase of gain. R3 1Ω Frequency stability Danger of oscillation at hight frequencies with inductive loads. R4 100 Ω Increaseing of output swing with low Vs. C1 2.2 µF Input DC decoupling. C2 0,1 µF Supply voltage bypass. C3 2.2 µF Inverting input DC decoupling. Increase of the switch-on noise Higher low frequency cutoff. 0.1µF C4 10 µF Ripple Rejection. Increase of SVR. Increase of the switch-on time. Degradation of SVR. 2.2 µF 100 µF C5 47 µF Bootstrap Increase of the distorsion at low frequency 10 mF 100 µF C6 0.22 µF Frequency stability. Danger of oscillation. C7 1000 µF Output DC decoupling. Higher low frequency cutoff. R1/9 47Ω Lower noise. Higher low frequency cutoff. Higher noise. 330 Ω 0.1 µF Danger of oscillations. 9/12 TDA1908 THERMAL SHUT-DOWN The presence of a thermal limiting circuit offers the following advantages: 1) An overload on the output (even if it is permanent), or an abovelimit ambienttemperature can be easily supported since the Tj cannot be higher than 150°C. 2) The heatsink can have a smaller factor of safety compared with that of a conventional circuit. There is no possibility of device damage due to high junction temperature. Figure 24. Output power and drain current vs. case temperature If, for any reason, the junction temperature increase up to 150°C, the thermal shut-down simply reduces the power dissipation and the current consumption. The maximum allowable power dissipation depends upon the size of the external heatsink (i.e. its thermal resistance); fig. 25 shows the dissipable power as a function of ambient temperature for different thermal resistance. Figure 25. Output power and drain current vs. case temperature Fi g ur e 2 6. Max i mum power dissipation vs. ambient temperature MOUNTING INSTRUCTIONS The thermal power dissipated in the circuit may be removed by soldering the tabs to a copper area on the PC board (see Fig. 27). Figure 27. Mounding example 10/12 During soldering, tab temperature must not exceed 260°C and the soldering time must not be longer than 12 seconds. Fi gu re 2 8. Max imu m power dissipation and thermal resistance vs. side ” ” TDA1908 FINDIP PACKAGE MEHANICAL DATA mm DIM. MIN. inch MAX. MIN. 3.8 4.05 0.150 0.159 a1 1.5 1.75 0.059 0.069 b 0.55 0.6 0.022 0.024 b1 0.3 0.35 0.012 A TYP. TYP. 0.014 c 1.32 0.052 c1 0.94 0.037 D 19.2 E 16.8 E1 4.86 E2 10.11 10.81 0.398 e 2.29 2.54 2.79 0.090 e3 17.43 17.78 18.13 0.686 17.2 e4 19.9 0.756 17.6 0.661 5.56 0.191 0.783 0.677 0.693 0.219 0.426 7.62 0.100 0.110 0.700 0.714 0.300 e5 7.27 7.62 7.97 e6 12.35 12.7 F 6.3 F1 6.1 G MAX. 0.286 0.300 13.05 0.486 0.500 7.1 0.248 0.280 6.7 0.240 0.264 9.8 0.314 0.514 0.386 I 7.8 8.6 0.307 0.339 K 6.1 6.5 0.240 0.256 L 2.5 2.9 0.098 0.114 M 2.5 3.1 0.098 0.122 G K L M a1 I A e4 b c c1 e5 e E1 e6 E2 e3 E b1 D 7 1 6 F 12 F1 D1 FINDIP 11/12 TDA1908 Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics 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 SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. 1994 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A. 12/12