TDA1905 Datasheet, PDF (11/14 Pages) STMicroelectronics – 5W AUDIO AMPLIFIER WITH MUTING

TDA1905
APPLICATION SUGGESTION
The recommended values of the external components are those shown on the application circuit of fig. 21.
When the supply voltage Vs is less than 10V, a 100Ω resistor must be connected between pin 2 and pin 3
in order to obtain the maximum output power.
Different values can be used. The following table can help the designer.
Component
Raccom.
value
Purpose
Rg + R1
10KΩ Input signal imped.
for muting operation
R₂
10KΩ
Feedback resistors
R₃
100Ω
Larger than
recommended value
Smaller than
Allowed range
recommended value
Min. Max.
Increase of the
attenuation in muting-on
condition. Decrease of
the input sensitivity.
Decrease of the attenu-
ation in muting on
condition.
Increase of gain.
Decrease of gain.
9 R₃
Increase quiescent
current.
Decrease of gain.
Increase of gain.
1KΩ
R₄
1KΩ Frequency stability Danger of oscillation at
high frequencies with
inductive loads.
R5
100Ω Increase of the output
swing with low supply
voltage.
47 330
P₁
20KΩ Volume potentiometer Increase of the
switch-on noise.
Decrease of the input
impedance and of the
input level.
10KΩ 100KΩ
C1
Input DC
C2
0.22µF decoupling.
C3
Higher cost
lower noise.
Higher low
frequency cutoff.
Higher noise.
C4
2.2µF Inverting input DC
Increase of the switch- Higher low frequency 0.1µF
decoupling.
on noise.
cutoff.
C5
0.1µF Supply voltage
bypass.
Danger of
oscillations.
C₆
10µF Ripple rejection
Increase of SVR
increase of the
switch-on time
Degradation of SVR
2.2µF 100µF
C7
47µF Bootstrap.
Increase of the
distortion at low
frequency.
10µF 100µF
C₈
0.22µF Frequency stability.
Danger of oscillation.
C₉
1000µF Output DC decoupling.
Higher low frequency
cutoff.
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