Datasheet TDA2005 (STMicroelectronics) - 9

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TDA2005 Electrical specifications 2.3.2 Bridge amplifier design
The following considerations can be useful when designing a bridge amplifier.
Table 5. Bridge amplifier design Parameter Single ended Bridge
1 V -- –  – o max Peak output voltage (before clipping) V 2V V 2V 2 s CEsat s CEsat 1 V – 2V V – 2V s CEsat s CEsat I -------------------- ------------------ o max Peak Output current (before clipping) 2 R R L L  2  2 1 V – 2V V – 2V s CEsat s CEsat P ------------------------ ---------------------- o max RMS output power (before clipping) 4 2R 2R L L Where: VCE sat = output transistors saturation voltage VS = allowable supply voltage RL = load impedance Voltage and current swings are twice for a bridge amplifier in comparison with single ended amplifier. In other words, with the same RL the bridge configuration can deliver an output power that is four times the output power of a single ended amplifier, while, with the same max output current the bridge configuration can deliver an output power that is four times the output power of a single ended amplifier, while, with the same max output current the bridge configuration can deliver an output power that is twice the output power of a single ended amplifier. Core must be taken when selecting VS and RL in order to avoid an output peak current above the absolute maximum rating. From the expression for IOmax, assuming VS = 14.4 V and VCE sat = 2 V, the minimum load that can be driven by TDA2005 in bridge configuration is: V – 2V – R s CEsat = ------------------ 14.4 4 = ---------- = 2.97 Lmin I 3.5 Omax The voltage gain of the bridge configuration is given by (see Figure 36): V R R G 0 = --- = 1 1 + ------------- 3 + ---- v V R 1  R  R  2 4 4 ----------  R + R  2 4 Doc ID 1451 Rev 6 9/25 Document Outline Table 1. Device summary 1 Schematic and pins connection diagrams Figure 1. Schematic diagram Figure 2. Pins connection diagram (top view) 2 Electrical specifications 2.1 Absolute maximum ratings Table 2. Absolute maximum ratings 2.2 Thermal data Table 3. Thermal data 2.3 Bridge amplifier section Figure 3. Test and application circuit (bridge amplifier) Figure 4. PC board and components layout of Figure 3 2.3.1 Electrical characteristics (bridge application) Table 4. Electrical characteristics (bridge application) Figure 5. Output offset voltage vs. supply voltage Figure 6. Distortion vs. output power (RL = 4 W) Figure 7. Distortion vs. output power (RL = 3.2 W) 2.3.2 Bridge amplifier design Table 5. Bridge amplifier design Table 6. High gain vs. Rx Figure 8. Bridge configuration 2.4 Stereo amplifier application Figure 9. Typical stereo application circuit 2.4.1 Electrical characteristics (stereo application) Table 7. Electrical characteristics (stereo application) Figure 10. Quiescent output voltage vs. supply voltage (stereo amplifier) Figure 11. Quiescent drain current vs. supply voltage (stereo amplifier) Figure 12. Distortion vs. output power (stereo amplifier) Figure 13. Output power vs. supply voltage, RL = 2 and 4 W (stereo amplifier) Figure 14. Output power vs. supply voltage, RL = 1.6 and 3.2 W (stereo amplifier) Figure 15. Distortion vs. frequency, RL = 2 and 4 W (stereo amplifier) Figure 16. Distortion vs. frequency, RL = 1.6 and 3.2 W (stereo amplifier) Figure 17. Supply voltage rejection vs. C3 (stereo amplifier) Figure 18. Supply voltage rejection vs. frequency (stereo amplifier) Figure 19. Supply voltage rejection vs. C2 and C3, GV = 390/1 W (stereo amplifier) Figure 20. Supply voltage rejection vs. C2 and C3, GV = 1000/10 W (stereo amplifier) Figure 21. Gain vs. input sensitivity RL = 4 W (stereo amplifier) Figure 22. Gain vs. input sensitivity RL = 2 W (stereo amplifier) Figure 23. Total power dissipation and efficiency vs. output power (bridge) Figure 24. Total power dissipation and efficiency vs. output power (stereo) 3 Application suggestion Table 8. Recommended values of the component of the bridge application circuit 4 Application information Figure 25. Bridge amplifier without boostrap Figure 26. PC board and components layout of Figure 25 Figure 27. Low cost bridge amplifier (GV = 42 dB) Figure 28. PC board and components layout of Figure 27 Figure 29. 10 + 10 W stereo amplifier with tone balance and loudness control Figure 30. Tone control response (circuit of Figure 29) Figure 31. 20 W bus amplifier Figure 32. Simple 20 W two way amplifier (FC = 2 kHz) Figure 33. Bridge amplifier circuit suited for low-gain applications (GV = 34 dB) Figure 34. Example of muting circuit 4.1 Built-in protection systems 4.1.1 Load dump voltage surge Figure 35. Suggested LC network circuit Figure 36. Voltage gain bridge configuration 4.1.2 Short circuit (AC and DC conditions) 4.1.3 Polarity inversion 4.1.4 Open ground 4.1.5 Inductive load 4.1.6 DC voltage 4.1.7 Thermal shut-down 4.1.8 Loudspeaker protection Figure 37. Maximum allowable power dissipation vs. ambient temperature Figure 38. Output power and drain current vs. case temperature (RL = 4 W) Figure 39. Output power and drain current vs. case temperature (RL = 3.2 W) 5 Package information Figure 40. Multiwatt11 mechanical data and package dimensions 6 Revision history Table 9. Document revision history