INTEGRATED CIRCUITS AN148 Audio amplifier with TDA1013A Author: D. Udo 1991 Dec Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 Author: D. Udo ABSTRACT The 9-pin SOT-110B-encapsulated TDA1013A is an audio power amplifier that has a DC volume control on-board. The device is designed for audio amplifier applications in TV sound channels. ELECTRONIC FILTER 4 At a supply voltage of 18V, the output power is about 4.4W into an 8 loudspeaker. INPUT The gain control range is >80dB with a DC control voltage from 8 to 3.5V. 8 3 DC GAIN CONTROL OUTPUT POWER AMP 9 Some basic information of the TDA1013A is dealt with in this application note. Detailed performance properties are given for an 18V into 8 application. SUPPLY VOLTAGE 2 TDA1013A 7 6 5 1 INTRODUCTION DC VOLUME CONTROL The TDA1013A has two functions: a DC volume control and audio power amplifier. SL00888 Figure 1. Some performance characteristics are: * Supply voltage range 15-35V * Max. repetitive peak current 1.5A * Max. non-repetitive peak current 3A * JTAB 9C * JA 45C * Input impedance 100k (Pins 5 and 8) * Output impedance 200 (Pin 6) (typ.) * Voltage gain DC control part 7dB (Pins 8 to 6) * Voltage gain power amplifier 30dB (Pins 5 to 2) APPLICATION CIRCUIT The complete application circuit is given in Figure 1. With high input impedance, C9 is necessary to filter-out RF input interferences. R3 in combination with C5 is used to limit the AF frequency bandwidth. The 470F power supply decoupling capacitor is C10. SL00889 Figure 2. Block Diagram and External Components 1991 Dec 2 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00890 Figure 3. Quiescent Current vs VCC SL00891 Figure 4. Midtap Voltage vs VCC the worst-case sinewave dissipation. The dissipation versus output MEASUREMENTS power for VCC=18V is given in Figure 6. Various measurements made in the circuit of Figure 1 are given. If not otherwise stated, the measurements are done at VCC=18V, RL=8, Distortion f=1kHz and TA=25C. The total harmonic distortion as a function of PO is shown in Figure 7 for signal frequencies of 1 and 10kHz (DC control voltage at Pin 7 is Quiescent Current Consumption constant 8V). In Figure 8 the same curve is given for f=1kHz but now The quiescent current as a function of VCC is given in Figure 3. At the output power is reduced by the DC control voltage (at d=10% VDC VCC=18V the maximum spread on 20 samples is indicated by arrows. Pin 7=8V). The distortion for 2.5W output power versus frequency is given in Figure 11. In Figure 9, the distortion of the DC gain-controlled Midtap Voltage preamplifier as a function of the signal excursion at Pin 6 is shown for The midtap voltage VA versus VCC at output Pin 2 is shown in Figure a DC control voltage (VDC Pin 7) of 8V. *4COL 4. Output Power and Dissipation The output power for d=10% as a function of VCC at Pin 2 and across the 8 loudspeaker load is given in Figure 5. The upper curve gives 1991 Dec 3 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00892 Figure 5. Output Power and Dissipation vs VCC SL00893 Figure 6. Dissipation vs PO 1991 Dec 4 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 Gain Control Noise Behavior The typical overall voltage gain (VDC Pin 7=8V) is 38dB. The gain control curve versus the DC control voltage on Pin 7 is shown in Figure 10. The A-weighted, IEC 179 standard, signal-to-noise ratio at maximum gain (VDC Pin 7=8V) is 68dB at RS=0 and related to PO=2.5W. Increasing RS has hardly any influence on this noise level. Typical S/N is 74dB. Frequency Characteristic The frequency characteristic is presented in Figure 12. The -3dB bandwidth is from 32Hz to 20kHz. CONCLUSION The TDA1013A is a suitable IC as an audio amplifier in TV receivers. It delivers an output power of about 4.4W in RL=8 at VCC=18V. An 80dB DC gain control is incorporated. Power Bandwidth The power bandwidth (d=10%) is given in Figure 13. The low frequency behavior is determined by the value of the output electrolytic C7 . Supply Voltage Ripple Rejection The supply voltage ripple rejection versus frequency is shown in Figure 14 for RS=0 and 10k. Ripple voltage on Pin 3 is 500mVRMS. SL00894 Figure 7. Distortion vs PO 1991 Dec 5 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00895 Figure 8. 1991 Dec 6 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00896 Figure 9. Distortion of Control Amplifier at Pin 6 1991 Dec 7 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00897 Figure 10. Typical Control Curve DC Control Voltage at Pin 7 SL00898 Figure 11. Distortion at PO = 2.5W vs Frequency (At Pin 2 of IC) 1991 Dec 8 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00899 Figure 12. Frequency Characteristic SL00900 Figure 13. Power Bandwidth 1991 Dec 9 Philips Semiconductors Application note Audio amplifier with TDA1013A AN148 SL00901 Figure 14. Ripple Rejection vs Frequency 1991 Dec 10