TDA7492 50 W + 50 W dual BTL class-D audio amplifier Features ■ 50 W + 50 W continuous output power at THD = 10% with RL = 6 Ω and VCC = 25 V ■ 40 W + 40 W continuous output power at THD = 10% with RL = 8 Ω and VCC = 25 V ■ Wide-range single-supply operation (8 - 26 V) ■ High efficiency (η = 90%) ■ Four selectable, fixed gain settings of nominally 21.6 dB, 27.6 dB, 31.1 dB and 33.6 dB ■ Differential inputs minimize common-mode noise ■ Standby and mute features ■ Short-circuit protection ■ Thermal overload protection ■ Externally synchronizable ■ ECOPACK®, environmentally-friendly package PowerSSO-36 with exposed pad up Description The TDA7492 is a dual BTL class-D audio amplifier with single power supply designed for LCD TVs and monitors. Thanks to the high efficiency and exposed-pad-up (EPU) package only a simple heatsink is required. Table 1. Device summary Order code Operating temp. range Package Packaging TDA7492 0 to 70 °C PowerSSO-36 EPU Tube TDA749213TR 0 to 70 °C PowerSSO-36 EPU Tape and reel September 2011 Doc ID 14926 Rev 5 1/32 www.st.com 1 Contents TDA7492 Contents 1 Device block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 4 2.1 Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 Pin list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.3 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Characterization curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.1 Characterizations for 6-Ω loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2 Characterizations for 8-Ω loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.3 Characterizations for 4-Ω loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.4 Test board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5 Applications circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6 Applications information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 7 2/32 6.1 Mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.2 Gain setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.3 Input resistance and capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.4 Internal and external clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.4.1 Master mode (internal clock) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.4.2 Slave mode (external clock) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.5 Output low-pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.6 Protection functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.7 Diagnostic output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.8 Heatsink requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Doc ID 14926 Rev 5 TDA7492 8 Contents Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Doc ID 14926 Rev 5 3/32 List of tables TDA7492 List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. 4/32 Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Pin description list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Electrical specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Mode settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Gain settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 How to set up SYNCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 PowerSSO-36 EPU dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Doc ID 14926 Rev 5 TDA7492 List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Internal block diagram (showing one channel only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Pin connections (top view, PCB view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Output power vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 THD vs. output power (1 kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 THD vs. output power (100 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 THD vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 FFT performance (0 dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 FFT performance (-60 dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Output power vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 THD vs. output power (1 kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 THD vs. output (100 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 THD vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 FFT performance (0 dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 FFT performance (-60 dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Output power vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 THD vs. output power (1 kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 THD vs. output (100 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 THD vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 FFT performance (0 dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 FFT performance (-60 dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Test board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Applications circuit for class-D amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Standby and mute circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Turn on/off sequence for minimizing speaker “pop” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Device input circuit and frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Master and slave connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Typical LC filter for a 8-Ω speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Typical LC filter for a 4-Ω speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Behavior of pin DIAG for various protection conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 PowerSSO-36 EPU outline drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Doc ID 14926 Rev 5 5/32 Device block diagram 1 TDA7492 Device block diagram Figure 1 shows the block diagram of one of the two identical channels of the TDA7492. Figure 1. 6/32 Internal block diagram (showing one channel only) Doc ID 14926 Rev 5 TDA7492 Pin description 2 Pin description 2.1 Pinout Figure 2. Pin connections (top view, PCB view) SUB GND 1 SVCC OUTPB 2 34 VREF OUTPB 3 33 INNB PGNDB 4 32 INPB PGNDB 5 31 GAIN1 PVCCB 6 30 GAIN0 PVCCB 7 29 SVR OUTNB 8 28 DIAG OUTNB 9 27 SGND OUTNA 10 26 VDDS OUTNA 11 25 SYNCLK PVCCA 12 24 ROSC PVCCA 13 23 INNA PGNDA 14 36 VSS 35 PGNDA 15 22 INPA EP exposed pad up Connect to ground 21 MUTE OUTPA 16 OUTPA 17 20 STBY 19 VDDPW Doc ID 14926 Rev 5 PGND 18 7/32 Pin description 2.2 TDA7492 Pin list Table 2. Pin description list Number 8/32 Name Type Description 1 SUB_GND PWR Connect to the frame 2,3 OUTPB O Positive PWM for right channel 4,5 PGNDB PWR Power stage ground for right channel 6,7 PVCCB PWR Power supply for right channel 8,9 OUTNB O Negative PWM output for right channel 10,11 OUTNA O Negative PWM output for left channel 12,13 PVCCA PWR Power supply for left channel 14,15 PGNDA PWR Power stage ground for left channel 16,17 OUTPA O Positive PWM output for left channel 18 PGND PWR Power stage ground 19 VDDPW O 3.3-V (nominal) regulator output referred to ground for power stage 20 STBY I Standby mode control 21 MUTE I Mute mode control 22 INPA I Positive differential input of left channel 23 INNA I Negative differential input of left channel 24 ROSC O Master oscillator frequency-setting pin 25 SYNCLK I/O Clock in/out for external oscillator 26 VDDS O 3.3-V (nominal) regulator output referred to ground for signal blocks 27 SGND PWR Signal ground 28 DIAG O Open-drain diagnostic output 29 SVR O Supply voltage rejection 30 GAIN0 I Gain setting input 1 31 GAIN1 I Gain setting input 2 32 INPB I Positive differential input of right channel 33 INNB I Negative differential input of right channel 34 VREF O Half VDDS (nominal) referred to ground 35 SVCC PWR Signal power supply 36 VSS O 3.3-V (nominal) regulator output referred to power supply - EP - Exposed pad for heatsink, to be connected to GND Doc ID 14926 Rev 5 TDA7492 Electrical specifications 3 Electrical specifications 3.1 Absolute maximum ratings Table 3. Absolute maximum ratings Symbol 3.2 Value Unit VCC DC supply voltage for pins PVCCA, PVCCB, SVCC 30 V VI Voltage limits for input pins STBY, MUTE, INNA, INPA, INNB, INPB, GAIN0, GAIN1 -0.3 - 3.6 V Top Operating temperature 0 to 70 °C Tj Junction temperature -40 to 150 °C Tstg Storage temperature -40 to 150 °C Thermal data Table 4. 3.3 Parameter Thermal data Symbol Parameter Rth j-case Thermal resistance, junction to case Min - Typ 2 Max 3 Unit °C/W Electrical specifications Unless otherwise stated, the results in Table 5 below are given for the conditions: VCC = 25 V, RL (load) = 8 Ω, ROSC = R3 = 39 kΩ, C8 = 100 nF, f = 1 kHz, GV = 21.6 dB and Tamb = 25 °C. Table 5. Symbol Electrical specifications Parameter Condition Min Typ Max Unit VCC Supply voltage for pins PVCCA, PVCCB, SVCC - 8 - 26 V Iq Total quiescent current Without LC - 26 35 mA IqSTBY Quiescent current in standby - - 2.5 5.0 µA Play mode - - ±100 VOS Output offset voltage Mute mode - - ±60 IOCP Overcurrent protection threshold RL = 0 Ω 4.8 6.0 - A Tj Junction temperature at thermal shutdown - - 150 - °C Ri Input resistance Differential input 48 60 - kΩ VOVP Overvoltage protection threshold - 28 29 - V mV Doc ID 14926 Rev 5 9/32 Electrical specifications Table 5. TDA7492 Electrical specifications (continued) Symbol Parameter Condition VUVP Undervoltage protection threshold RdsON Power transistor on resistance Po Output power Po Min Typ - - - 7 High side - 0.2 - Low side - 0.2 - THD = 10% - 40 - THD = 1% - 32 - RL = 6 Ω, THD = 10%, VCC = 25V - 50 - RL = 6 Ω, THD = 1% VCC = 25V - 40 - Unit V Ω W Output power W PD Dissipated power Po =40W +40 W, THD = 10% - 8.0 - W η Efficiency Po = 40 W + 40W 80 90 - % THD Total harmonic distortion Po = 1 W - 0.1 0.4 % GAIN0 = L, GAIN1 = L 20.6 21.6 22.6 GAIN0 = L, GAIN1 = H 26.6 27.6 28.6 GAIN0 = H, GAIN1 = L 30.1 31.1 32.1 GAIN0 = H, GAIN1 = H 32.6 33.6 34.6 GV Closed-loop gain dB ΔGV Gain matching - - - ±1 dB CT Cross talk f = 1 kHz - 50 - dB 20 - Total input noise A Curve, GV = 20 dB - eN f = 22 Hz to 22 kHz - 25 35 µV SVRR Supply voltage rejection ratio fr = 100 Hz, Vr = 0.5 V, CSVR = 10 µF 40 50 - dB Tr, Tf Rise and fall times - - 50 - ns fSW Switching frequency Internal oscillator 290 310 330 kHz 250 - 400 With external oscillator (2) 250 - 400 2.3 - - - - 0.8 60 80 - fSWR Output switching frequency Range VinH Digital input high (H) VinL Digital input low (L) AMUTE Mute attenuation With internal oscillator (1) kHz VMUTE = 1 V V 1. fSW = 106 / ((16 * ROSC + 182) * 4) kHz, fSYNCLK = 2 * fSW with R3 = 39 kΩ (see Figure 28.). 2. fSW = fSYNCLK / 2 with the frequency of the external oscillator. 10/32 Max Doc ID 14926 Rev 5 dB TDA7492 4 Characterization curves Characterization curves The general test conditions used for producing the characterization curves can be summarized as follows: Test board: SZ LAB TDA7492 slug-up demo board Test frequency: 1 kHz (also 100 Hz for THD vs. output power only) Output power: 1 W ● ● ● For 6-Ω loads – test voltage: 25 V – LC filter: L = 22 µH and C = 220 nF For 8-Ω loads – test voltage: 25 V – LC filter: L = 33 µH and C = 220 nF For 4-Ω loads – test voltage: 20 V – LC filter: L = 15 µH and C = 470 nF. Figure 28 on page 22 shows the circuit with which the characterization curves, shown in the next sections, were measured. Figure 27 on page 21 shows the PCB layout. Characterizations for 6-Ω loads Figure 3. Output power vs. supply voltage 3RXWYV9FF Test conditions: Vcc = 15 - 25 V, RL = 6 Ω, Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, Gv = 30 dB, Tamb = 25r C 3RXW: 4.1 10% THD 1% THD Specification limit: Typical: Vs = 25 V, RL = 6 Ω, Po = 50 W atTHD = 10%, 9FF9 Po = 40 W atTHD = 1% Doc ID 14926 Rev 5 11/32 Characterization curves Figure 4. TDA7492 THD vs. output power (1 kHz) 10 5 Test conditions: THD % Vcc = 25 V, 2 RL = 6 Ω, Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, 1 0.5 Gv = 30 dB, 0.2 Tamb = 25r C 0.1 Specification limit: 0.05 Typical: 0.02 Po = 50 W at THD = 10% 0.01 100m 200m 500m 1 2 5 10 20 60 Output Power (W) Figure 5. THD vs. output power (100 Hz) 10 Test conditions: Vcc = 25 V, RL = 6 Ω, Rosc = 39 kΩ, Cosc = 100 nF, f = 100 Hz, 5 THD % 2 1 0.5 Gv = 30 dB, 0.2 Tamb = 25r C 0.1 Specification limit: Typical: 0.05 0.02 Po = 50 W at THD = 10% 0.01 100m 200m 500m 1 2 5 10 Output power (W) 12/32 Doc ID 14926 Rev 5 20 60 TDA7492 Characterization curves Figure 6. THD vs. frequency 0.5 0.4 Test conditions: 0.3 Vcc = 25 V, RL = 6 Ω, 0.2 Rosc = 39 kΩ, Cosc = 100 nF, THD % f = 1 kHz, 0.1 Gv = 30 dB, 0.07 0.06 Po = 1 W, 0.05 0.04 Tamb = 25r C 0.03 0.02 Specification limit: Typical: THD < 0.4% 0.01 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Figure 7. Frequency response +1 Test conditions: Vcc = 25 V, +0.5 -0 dBrA RL = 6 Ω, -0.5 -1 Rosc = 39 kΩ, Cosc = 100 nF, -1.5 f = 1 kHz, -2 Gv = 30 dB, -2.5 Po = 1 W, -3 Tamb = 25r C -3.5 -4 Specification limit: -4.5 -5 Max: +/-3 dB (20 Hz to 20 kHz) -5.5 -6 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Figure 8. Crosstalk -60 T Test conditions: Vcc = 25 V, RL = 6 Ω, Crosstalk dB T TT -75 -80 f = 1 kHz, -85 Gv = 30 dB, -90 Tamb = 25r C T -70 Rosc = 39 kΩ, Cosc = 100 nF, Po = 1 W T -65 -95 -100 -105 Specification limit: -110 Typical: > 50 dB (at f = 1 kHz) -115 -120 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Doc ID 14926 Rev 5 13/32 Characterization curves Figure 9. TDA7492 FFT performance (0 dB) +10 +0 Test conditions: -10 Vcc = 25 V, RL = 6 Ω, -20 dBrA -30 -40 Rosc = 39 kΩ, Cosc = 100 nF, -50 f = 1 kHz, -60 Gv = 30 dB, -70 Po = 1 W, -80 Tamb = 25r C -90 -100 -110 Specification limit: -120 Typical: > 60 dB -130 for the harmonic frequency -140 -150 20 50 100 200 500 1k 2k 5k 10k 20k 2k 5k 10k 20k Frequency (Hz) Figure 10. FFT performance (-60 dB) +10 +0 Test conditions: -10 Vcc = 25 V, RL = 6 Ω, Rosc = 39 kΩ, Cosc = 100 nF, -20 dBrA -30 -40 -50 f = 1 kHz, Gv = 30 dB, Po = -60 dB (at 1 W = 0 dB) Tamb = 25r C -60 -70 -80 -90 -100 -110 Specification limit: -120 Typical: > 90 dB -130 for the harmonic frequency -140 -150 20 50 100 200 500 1k Frequency (Hz) 14/32 Doc ID 14926 Rev 5 TDA7492 Characterizations for 8-Ω loads Figure 11. Output power vs. supply voltage Test conditions: 3RXWYV9FF Vcc = 5 - 25 V, RL = 8 Ω, Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, Gv = 30 dB, Tamb = 25r C 3RXW: 4.2 Characterization curves Specification limit: 10% THD 1% THD Typical: Vs = 25 V, RL = 8 Ω, Po = 40 W at THD = 10%, 9FF9 Po = 32 W at THD = 1% Figure 12. THD vs. output power (1 kHz) 10 Test conditions: 5 Vcc = 25 V, THD RL = 8 Ω, % Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, 2 1 0.5 Gv = 30 dB, Tamb = 25r C 0.2 0.1 Specification limit: 0.05 Typical: 0.02 Po = 40 W at THD = 10% 0.01 100m 200m 500m 1 2 5 10 20 50 Output power (W) Doc ID 14926 Rev 5 15/32 Characterization curves TDA7492 Figure 13. THD vs. output (100 Hz) 10 Test conditions: Vcc = 25 V, RL = 8 Ω, 5 THD % 2 Rosc = 39 kΩ, Cosc = 100 nF, 1 f = 100 Hz, 0.5 Gv = 30 dB, Tamb = 25r C 0.2 0.1 Specification limit: 0.05 Typical: Po = 40 W at THD = 10% 0.02 0.01 100m 200m 500m 1 2 5 10 20 50 Output power (W) Figure 14. THD vs. frequency 0.5 0.4 Test conditions: 0.3 Vcc = 25 V, THD RL = 8 Ω, % 0.2 Rosc = 39 kΩ, Cosc = 100 nF, 0.1 f = 1 kHz, Gv = 30 dB, 0.07 0.06 Po = 1 W, 0.05 Tamb = 25r C 0.04 0.03 Specification limit: 0.02 Typical: THD < 0.4% 0.01 20 50 100 200 500 1k 2k 5k 10k Frequency (Hz) Figure 15. Frequency response +1 +0.5 Test conditions: Vcc = 25 V, RL = 8 Ω, Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, Gv = 30 dB, Po = 1 W, -0 dBrA -0.5 -1 -1.5 -2 -2.5 -3 Tamb = 25r C -3.5 Specification limit: -4.5 -4 Max: +/-3 dB (20 Hz to 20 kHz) -5 -5.5 -6 20 50 100 200 500 1k Frequency (Hz) 16/32 Doc ID 14926 Rev 5 2k 5k 10k 20k 20k TDA7492 Characterization curves Figure 16. Crosstalk -60 Test conditions: Vcc = 25 V, RL = 8 Ω, T T T T TT T T -65 Crosstalk -70 dB -75 Rosc = 39 kΩ, Cosc = 100 nF, -80 f = 1 kHz, -85 Gv = 30 dB, -90 Po = 1 W, -95 Tamb = 25r C -100 -105 Specification limit: -110 Typical: > 50 dB (at f = 1 kHz) -115 -120 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Figure 17. FFT performance (0 dB) +10 +0 Test conditions: Vcc = 25 V, -10 dBrA RL = 8 Ω, -20 -30 Rosc = 39 kΩ, Cosc = 100 nF, -40 f = 1 kHz, -50 Gv = 30 dB, -60 -70 Po = 1 W, -80 Tamb = 25r C -90 -100 -110 Specification limit: -120 Typical: > 60 dB -130 for the harmonic frequency -140 -150 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Figure 18. FFT performance (-60 dB) +10 +0 Test conditions: -10 Vcc = 25 V, dBrA -20 RL = 8 Ω, -30 Rosc = 39 kΩ, Cosc = 100 nF, -40 f = 1 kHz, -50 Gv = 30 dB, -60 -70 Po = -60 dB (at 1 W = 0 dB) Tamb = 25r C -80 -90 -100 -110 Specification limit: -120 Typical: > 90 dB -130 for the harmonic frequency -140 -150 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Doc ID 14926 Rev 5 17/32 Characterization curves 4.3 TDA7492 Characterizations for 4-Ω loads Figure 19. Output power vs. supply voltage Test conditions: 3RXWYV9FF Vcc = 15 - 22 V, RL = 4 Ω, f = 1 kHz, Gv = 20 dB, Tamb = 25r C 3RXW: Rosc = 39 kΩ, Cosc = 100 nF, Specification limit: Typical: 10% THD 1% THD Vs = 20 V, RL = 4 Ω, Po = 47 W at THD = 10%, 9FF9 Po = 38 W at THD = 1% Figure 20. THD vs. output power (1 kHz) 10 Test conditions: 5 Vcc = 20 V, THD + N RL = 4 Ω, % Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, 2 1 0.5 Gv = 20 dB, Tamb = 25r C 0.2 0.1 Specification limit: 0.05 Typical: Po = 38 W at THD = 1% 0.02 0.01 100m 200m 500m 1 2 5 Output power (W) 18/32 Doc ID 14926 Rev 5 10 20 50 TDA7492 Characterization curves Figure 21. THD vs. output (100 Hz) 10 Test conditions: 5 Vcc = 20 V, THD + N RL = 4 Ω, % 2 Rosc = 39 kΩ, Cosc = 100 nF, 1 f = 100 Hz, 0.5 Gv = 20 dB, Tamb = 25r C 0.2 0.1 Specification limit: 0.05 Typical: Po = 38 W at THD = 1% 0.02 0.01 100m 200m 500m 1 2 5 10 20 50 Output power (W) Figure 22. THD vs. frequency 0.5 0.4 Test conditions: 0.3 Vcc = 20 V, RL = 4 Ω, THD + N 0.2 % Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, 0.1 Gv = 20 dB, 0 dB at f = 1 kHz, 0.07 0.06 Po = 1 W, 0.05 Tamb = 25r C 0.04 0.03 Specification limit: 0.02 Typical: THD < 0.4% 0.01 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Figure 23. Frequency response +1 Test conditions: +0.75 +0.5 Vcc = 20 V, RL = 4 Ω, Rosc = 39 kΩ, Cosc = 100 nF, f = 1 kHz, Gv = 20 dB, 0 dB at f = 1 kHz, Po = 1 W, Tamb = 25r C +0.25 dBrA -0 -0.25 -0.5 -0.75 -1 -1.25 -1.5 -1.75 -2 Specification limit: Typical: Max: +/-3 dB (20 Hz to 20 kHz) -2.25 -2.5 -2.75 -3 20 50 100 200 500 1k 2k 5k 10k 20k Frequency (Hz) Doc ID 14926 Rev 5 19/32 Characterization curves TDA7492 Figure 24. Crosstalk -60 T Vcc = 20 V, RL = 4 Ω, T T T T -65 Test conditions: -70 Crosstalk -75 dB Rosc = 39 kΩ, Cosc = 100 nF, -80 f = 1 kHz, -85 Gv = 20 dB, -90 0 dB at f = 1 kHz, -95 Po = 1 W, -100 Tamb = 25r C -105 Specification limit: -110 Typical: > 50 dB (at f = 1 kHz) -115 -120 20 50 100 200 500 1k 2k 5k 10k 20k 2k 5k 10k 20k Frequency (Hz) Figure 25. FFT performance (0 dB) +10 +0 Test conditions: Vcc = 20 V, -10 dBrA RL = 4 Ω, -20 -30 Rosc = 39 kΩ, Cosc = 100 nF, -40 f = 1 kHz, -50 Gv = 20 dB, -60 0 dB at f = 1 kHz, -70 -80 Po = 1 W, -90 Tamb = 25r C -100 -110 Specification limit: -120 Typical: > 60 dB -130 for the harmonic frequency -140 -150 20 50 100 200 500 1k Frequency (Hz) Figure 26. FFT performance (-60 dB) +10 +0 Test conditions: -10 Vcc = 20 V, RL = 4 Ω, -20 dBrA -30 Rosc = 39 kΩ, Cosc = 100 nF, -40 f = 1 kHz, -50 Gv = 20 dB, -60 0 dB at f = 1 kHz, -70 -80 Po = 1 W, Tamb = 25r C -90 -100 -110 Specification limit: -120 Typical: > 90 dB -130 for the harmonic frequency -140 -150 20 50 100 200 500 1k Frequency (Hz) 20/32 Doc ID 14926 Rev 5 2k 5k 10k 20k TDA7492 Test board Figure 27. Test board layout 2. Test board 4.4 Characterization curves Doc ID 14926 Rev 5 21/32 Applications circuit 5 TDA7492 Applications circuit Figure 28. Applications circuit for class-D amplifier & Q) & Q) 6*1' & Q) & Q) 6*1' & Q) 68%B*1' 2873$ / ,13$ 2873$ X+ ,11$ 5 & Q) - & & 9''6 Q) Q) ',$* 39&&$ ',$* 9''3: / 2871$ 3*1' - 526& *$,1 ,1/ ,1/ & ,15 5 Q) - & 9''6 *$,1 - 6*1' )RU - Q) / 2873% X+ 39&&% 39&&% 966 ,13% 3*1'% 2871% & 2871% & Q) 9 6*1' 6 087( 9 6*1' 6*1' & X) ,& 6*1' 5 N 5 9&& ,1 /&= ,11% Q) 6*1' 6*1' 932:(56833/< Q) & & S) Q) 2875 2875 & X) 9 6*1' & X) 9 6*1' LC filter components /&),/7(5&20321(17 Load /RDG L1,L2,L3,L4 C20,C26 && //// 4 RKP Ω 15 µHX+ 470 nF Q) 6 RKP Ω 22 µHX+ Q) 220 nF 8 RKP Ω 33 µHX+ RKP 16 Ω X+ 68 µH Q) 220 nF Input settings for gain: STBY : MUTE Mode GAIN0 : GAIN1 Nominal gain Standby Standby Mute Play 0V:0V 0 V : 3.3 V 3.3 V : 0 V 3.3 V : 3.3 V 21.6 dB 27.6 dB 31.1 dB 33.6 dB Doc ID 14926 Rev 5 Q) 220 nF Input settings for standby, mute and play: 0V:0V 0 V : 3.3 V 3.3 V : 0 V 3.3 V : 3.3 V 22/32 695 7'$36OXJGRZQ Class-D amplifier &/$66'$03/,),(5 6*1' 6*1' 087( N 6*1' 6*1' - X+ 95() & X) 9 67%< & X) 9 N 5 & Q) *1' & / 5 N 6*1' & 6 67%< 287 Q) *1' Q) 6*1' & Q) Q) & 3*1'% 9&& & 5 69&& 5 & ,QSXW X) 9 2873% . ,15 6LQJOH(QGHG ,& 7'$3 TDA7492P 287/ - X+ 6<1&/. 6<1&/. 287/ Q) 6*1' & S) 2871$ Q) & 39&&$ & ,QSXW 5 6*1' 5 N - 5 5 )RU 9''6 6*1' 6LQJOH(QGHG 3*1'$ 3*1'$ TDA7492 Applications information 6 Applications information 6.1 Mode selection The three operating modes of the TDA7492 are set by the two inputs, STBY (pin 20) and MUTE (pin 21). ● Standby mode: all circuits are turned off, very low current consumption. ● Mute mode: inputs are connected to ground and the positive and negative PWM outputs are at 50% duty cycle. ● Play mode: the amplifiers are active. The protection functions of the TDA7492 are enabled by pulling down the voltages of the STBY and MUTE inputs shown in Figure 29. The input current of the corresponding pins must be limited to 200 µA. Table 6. Mode settings Mode STBY MUTE L (1) Standby Mute H Play H X (don’t care) (1) L H 1. Drive levels defined in Table 5: Electrical specifications on page 9 Figure 29. Standby and mute circuits Standby 3.3 V 0V STBY R2 30 kΩ C7 2.2 µF R4 30 kΩ C15 2.2 µF Mute MUTE 3.3 V 0V TDA7492 Figure 30. Turn on/off sequence for minimizing speaker “pop” Doc ID 14926 Rev 5 23/32 Applications information 6.2 TDA7492 Gain setting The gain of the TDA7492 is set by the two inputs, GAIN0 (pin 30) and GAIN1 (pin31). Internally, the gain is set by changing the feedback resistors of the amplifier. Table 7. Gain settings GAIN0 6.3 GAIN1 Nominal gain, Gv (dB) 0 0 21.6 0 1 27.6 1 0 31.1 1 1 33.6 Input resistance and capacitance The input impedance is set by an internal resistor Ri = 60 kΩ (typical). An input capacitor (Ci) is required to couple the AC input signal. The equivalent circuit and frequency response of the input components are shown in Figure 31. For Ci = 470 nF the high-pass filter cutoff frequency is below 20 Hz: fc = 1 / (2 * π * Ri * Ci) Figure 31. Device input circuit and frequency response Rf Input signal 24/32 Ci Input pin Ri Doc ID 14926 Rev 5 TDA7492 6.4 Applications information Internal and external clocks The clock of the class-D amplifier can be generated internally or can be driven by an external source. If two or more class-D amplifiers are used in the same system, it is recommended that all devices operate at the same clock frequency. This can be implemented by using one TDA7492 as master clock, while the other devices are in slave mode, that is, externally clocked. The clock interconnect is via pin SYNCLK of each device. As explained below, SYNCLK is an output in master mode and an input in slave mode. 6.4.1 Master mode (internal clock) Using the internal oscillator, the output switching frequency, fSW, is controlled by the resistor, ROSC, connected to pin ROSC: fSW = 106 / ((ROSC * 16 + 182) * 4) kHz where ROSC is in kΩ. In master mode, pin SYNCLK is used as a clock output pin whose frequency is: fSYNCLK = 2 * fSW For master mode to operate correctly, then resistor ROSC must be less than 60 kΩ as given below in Table 8. 6.4.2 Slave mode (external clock) In order to accept an external clock input the pin ROSC must be left open, that is, floating. This forces pin SYNCLK to be internally configured as an input as given in Table 8. The output switching frequency of the slave devices is: fSW = fSYNCLK / 2 Table 8. How to set up SYNCLK Mode ROSC SYNCLK Master ROSC < 60 kΩ Output Slave Floating (not connected) Input Figure 32. Master and slave connection Master Slave TDA7492 TDA7492 ROSC SYNCLK Output Cosc 100 nF SYNCLK ROSC Input Rosc 39 kΩ Doc ID 14926 Rev 5 25/32 Applications information 6.5 TDA7492 Output low-pass filter To avoid EMI problems, it may be necessary to use a low-pass filter before the speaker. The cutoff frequency should be larger than 22 kHz and much lower than the output switching frequency. It is necessary to choose the L-C component values depending on the loud speaker impedance. Some typical values, which give a cutoff frequency of 27 kHz, are shown in Figure 33 and Figure 34 below. Figure 33. Typical LC filter for a 8-Ω speaker Figure 34. Typical LC filter for a 4-Ω speaker 26/32 Doc ID 14926 Rev 5 TDA7492 6.6 Applications information Protection functions The TDA7492 is fully protected against overvoltages, undervoltages, overcurrents and thermal overloads as explained here. Overvoltage protection (OVP) If the supply voltage exceeds the value for VOVP given in Table 5: Electrical specifications on page 9 the overvoltage protection is activated which forces the outputs to the high-impedance state. When the supply voltage drops to below the threshold value the device restarts. Undervoltage protection (UVP) If the supply voltage drops below the value for VUVP given in Table 5: Electrical specifications on page 9 the undervoltage protection is activated which forces the outputs to the high-impedance state. When the supply voltage recovers the device restarts. Overcurrent protection (OCP) If the output current exceeds the value for IOCP given in Table 5: Electrical specifications on page 9 the overcurrent protection is activated which forces the outputs to the high-impedance state. Periodically, the device attempts to restart. If the overcurrent condition is still present then the OCP remains active. The restart time, TOC, is determined by the R-C components connected to pin STBY. Thermal protection (OTP) If the junction temperature, Tj, reaches 145 °C (nominally), the device goes to mute mode and the positive and negative PWM outputs are forced to 50% duty cycle. If the junction temperature reaches the value for Tj given in Table 5: Electrical specifications on page 9 the device shuts down and the output is forced to the high-impedance state. When the device cools sufficiently the device restarts. 6.7 Diagnostic output The output pin DIAG is an open drain transistor. When the protection is activated it is in the high-impedance state. The pin can be connected to a power supply (<26 V) by a pull-up resistor whose value is limited by the maximum sinking current (200 µA) of the pin. Figure 35. Behavior of pin DIAG for various protection conditions VDD TDA7492 R1 DIAG Protection logic VDD Restart Restart Overcurrent protection OV, UV, OT protection Doc ID 14926 Rev 5 27/32 Applications information 6.8 TDA7492 Heatsink requirements As with most amplifiers, the power dissipated within the device depends primarily on the supply voltage, the load impedance and the output modulation level. The maximum estimated power dissipation for the TDA7492 is around 7 W. At 25 °C ambient a heatsink having Rth =15 °C/W is sufficient for sine-wave testing at maximum power. A musical program, however, dissipates about 40% less power than this and a heatsink with Rth = 25 °C/W is thus recommended. Even at the maximum recommended ambient temperature for consumer applications of 50 °C there is still a clear safety margin before the maximum junction temperature (150 °C) is reached. 28/32 Doc ID 14926 Rev 5 TDA7492 Package mechanical data The TDA7492 comes in a 36-pin PowerSSO package with exposed pad up (EPU). Figure 36 shows the package outline and Table 9 gives the dimensions. Figure 36. PowerSSO-36 EPU outline drawing h x 45° 7 Package mechanical data Doc ID 14926 Rev 5 29/32 Package mechanical data Table 9. TDA7492 PowerSSO-36 EPU dimensions Dimensions in mm Dimensions in inches Symbol Min Typ Max Min Typ Max A 2.15 - 2.45 0.085 - 0.096 A2 2.15 - 2.35 0.085 - 0.093 a1 0 - 0.10 0 - 0.004 b 0.18 - 0.36 0.007 - 0.014 c 0.23 - 0.32 0.009 - 0.013 D 10.10 - 10.50 0.398 - 0.413 E 7.40 - 7.60 0.291 - 0.299 e - 0.5 - - 0.020 - e3 - 8.5 - - 0.335 - F - 2.3 - - 0.091 - G - - 0.10 - - 0.004 H 10.10 - 10.50 0.398 - 0.413 h - - 0.40 - - 0.016 k 0 - 8 degrees - - 8 degrees L 0.60 - 1.00 0.024 - 0.039 M - 4.30 - - 0.169 - N - - 10 degrees - - 10 degrees O - 1.20 - - 0.047 - Q - 0.80 - - 0.031 - S - 2.90 - - 0.114 - T - 3.65 - - 0.144 - U - 1.00 - - 0.039 - X 4.10 - 4.70 0.161 - 0.185 Y 4.90 - 7.10 0.193 - 0.280 In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. 30/32 Doc ID 14926 Rev 5 TDA7492 8 Revision history Revision history Table 10. Document revision history Date Revision 30-Jul-2008 1 Initial release. 4-Nov-2008 2 Updated VOS details in Table 5 Updated Chapter 4: Characterization curves on page 11. 3 Updated supply operating range to 8 V - 26 V on page 1 Changed C1 to C8 at beginning of Section 3.3 on page 9 Updated Table 5: Electrical specifications on page 9 for VCC min, Iq condition, VOS min/max, IOC, and added new parameter VUV Updated Figure 3: Test circuit for characterizations on page 10 Updated Figure 28: Applications circuit for class-D amplifier on page 22 Inserted brackets in equation in Table 5, footnote and in Section 6.4.1 on page 25 Updated values in UVP and OCP in Section 6.6 on page 27 Updated package presentation in Chapter 7 on page 29 and max vaules for A and A2 in Table 9: PowerSSO-36 EPU dimensions on page 30. 03-Sep-2009 4 Added text for exposed pad in Figure 2 on page 7 Added text for exposed pad in Table 2 on page 8 Removed Figure 3: Test circuit for characterizations since it is identical to apps circuit in Figure 28 on page 22 Moved section Test board on page 21 to end of chapter Updated package Y (Min) dimension in Table 9 on page 30 12-Sep-2011 5 Updated OUTNA in Table 2: Pin description list 15-Apr-2009 Changes Doc ID 14926 Rev 5 31/32 TDA7492 Please Read Carefully: Information in this document is provided solely in connection with ST products. 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The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2011 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 32/32 Doc ID 14926 Rev 5