TDA7245 Datasheet, PDF (5/11 Pages) STMicroelectronics – 5W AUDIO AMPLIFIER WITH MUTING AND STAND-BY

Figure 3: P.C. Board and Components Layout of the Circuit of fig 2 (1:1 scale)
TDA7245
APPLICATION SUGGESTIONS
The recommended values of the external components are those shown on the application circuit of fig.1.
Different values can be used. The following table can help the dsigner.
Component Rec. Value
R1
20KΩ
R2(*)
R3(*)
R4
C1
27KΩ
270Ω
1Ω
22µF
C2
47µF
C3
0.1µF
C4
2.2µF
C5
470µF
C6
0.22µF
C7
1000µF
Purpose
St-By Biasing
Feedback
Resistors
Frequency Stability
St-By Capacitor
SVR Capacitor
Input Capacitance
Inverting Input DC
Decoupling
Supply Voltage
Frequency Stability
Output DC Decoupling
Larger than Rec. Value
Incorrect St-By Function
Increase of Gain
Decrease of Gain
Danger of Oscillations
Longer ON/OFF Delay
Time at St-By IN/OUT
Worse Turn-On POP by
VS and St-By
Danger of Oscillations
Smaller than Rec. Value
Worse POP and Shorter
Delay at St-By Insertion
Decrease of Gain
Increase of Gain
Worse POP and Shorter
Delay at St-By insertion
Degradation of SVR
Higher Low Frequency
Cut-off
Higher Low Frequency
Cut-off
Danger of Oscillations
Higher Low Frequency
Cut-off
(*) The value of closed loop gain (GV = 1 + R2/R3) must be higher than 25dB.
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