AN148
Audio amplifier with TDA1013A
Author: D. Udo 1991 Dec
INTEGRATED CIRCUITS
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
Author: D. Udo
2
1991 Dec
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.
At a supply voltage of 18V, the output power is about 4.4W into an
8Ω loudspeaker.
The gain control range is >80dB with a DC control voltage from 8 to
3.5V.
Some basic information of the TDA1013A is dealt with in this
application note. Detailed performance properties are given for an
18V into 8Ω application.
INTRODUCTION
The TDA1013A has two functions: a DC volume control and audio
power amplifier.
Some performance characteristics are:
•Supply voltage range 15-35V
•Max. repetitive peak current 1.5A
•Max. non-repetitive peak current 3A
•θJTAB 9°C
•θJA 45°C
•Input impedance 100kΩ (Pins 5 and 8)
•Output impedance 200Ω (Pin 6) (typ.)
•Voltage gain DC control part 7dB (Pins 8 to 6)
•Voltage gain power amplifier 30dB (Pins 5 to 2)
INPUT 8
9
7 6 5 1
2
34
ELECTRONIC
FILTER SUPPLY
OUTPUT
DC GAIN
CONTROL
POWER
AMP
TDA1013A
DC VOLUME
CONTROL
VOLTAGE
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Figure 1.
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 470µF power supply decoupling capacitor is C10.
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Figure 2. Block Diagram and External Components
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 3
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Figure 3. Quiescent Current vs VCC
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Figure 4. Midtap Voltage vs VCC
MEASUREMENTS
Various measurements made in the circuit of Figure 1 are given. If not
otherwise stated, the measurements are done at VCC=18V, RL=8Ω,
f=1kHz and TA=25°C.
Quiescent Current Consumption
The quiescent current as a function of VCC is given in Figure 3. At
VCC=18V the maximum spread on 20 samples is indicated by arrows.
Midtap Voltage
The midtap voltage VA versus VCC at output Pin 2 is shown in Figure
4.
Output Power and Dissipation
The output power for d=10% as a function of VCC at Pin 2 and across
the 8Ω loudspeaker load is given in Figure 5. The upper curve gives
the worst–case sinewave dissipation. The dissipation versus output
power for VCC=18V is given in Figure 6.
Distortion
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
constant 8V). In Figure 8 the same curve is given for f=1kHz but now
the output power is reduced by the DC control voltage (at d=10% VDC
Pin 7=8V). The distortion for 2.5W output power versus frequency is
given in Figure 1 1. In Figure 9, the distortion of the DC gain–controlled
preamplifier as a function of the signal excursion at Pin 6 is shown for
a DC control voltage (VDC Pin 7) of 8V. *4COL
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 4
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Figure 5. Output Power and Dissipation vs VCC
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Figure 6. Dissipation vs PO
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 5
Gain Control
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.
Frequency Characteristic
The frequency characteristic is presented in Figure 12. The –3dB
bandwidth is from 32Hz to 20kHz.
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 10kΩ. Ripple voltage on Pin 3 is 500mVRMS.
Noise Behavior
The A–weighted, IEC 179 standard, signal–to–noise ratio at maximum
gain (VDC Pin 7=8V) is 68dB at RS=0Ω and related to PO=2.5W.
Increasing RS has hardly any influence on this noise level. T ypical S/N
is 74dB.
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=8Ω at VCC=18V. An
80dB DC gain control is incorporated.
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Figure 7. Distortion vs PO
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 6
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Figure 8.
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 7
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Figure 9. Distortion of Control Amplifier at Pin 6
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 8
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Figure 10. Typical Control Curve DC Control Voltage at Pin 7
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Figure 11. Distortion at PO = 2.5W vs Frequency (At Pin 2 of IC)
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 9
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Figure 12. Frequency Characteristic
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Figure 13. Power Bandwidth
Philips Semiconductors Application note
AN148Audio amplifier with TDA1013A
1991 Dec 10
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Figure 14. Ripple Rejection vs Frequency
