TDA7494 Datasheet, PDF (5/12 Pages) STMicroelectronics – 10W AMPLIFIER WITH DC VOLUME CONTROL

TDA7494
APPLICATION SUGGESTIONS
The recommended values of the external components are those shown on the application circuit of fig-
ure 1. Different values can be used; the following table can help the designer.
COMPONENT
R1
R2
R3
R4
R5
P1
C1
C2
C3
SUGGESTION
VALUE
3.3KΩ
3.3KΩ
100KΩ
100KΩ
10KΩ
50KΩ
1000µF
100nF
PURPOSE
Input switch circuit
Input switch circuit
Input switch time
constant
Volume control time
constant
Mute time constant
Volume control circuit
Supply voltage bypass
Supply voltage bypass
470nF
Input DC decoupling
C4
470nF
Input DC decoupling
C5
470nF
Input DC decoupling
C6
300nF
Input- switch time
constant
C7
300nF
Volume control time
constant
C8
470µF
Ripple Rejection
C9
1µF
Mute time constant
C10
470µF
Output DC decoupling
LARGER THAN
SUGGESTION
SMALLER THAN
SUGGESTION
Vpin #2 shifted downward Vpin #2 shifted upward
Vpin #2 shifted upward Vpin #2 shifted downward
Larger Input Switch Time Smaller input switch time
Larger Volume
Regulation Time
Larger mute on/off time
Smaller volume
regulation time
Smaller mute on/off time
Lower low frequency
cutoff
Lower low frequency
cutoff
Lower low frequency
cutoff
Danger of oscillation
Danger of oscillation
Higher low frequency
cutoff
Higher low frequency
cutoff
Higher low frequency
cutoff
Larger-Input- switch time Smaller input- switch time
Larger volume regulation
time
Better SVR
Larger mute on/off time
Lower low frequency
cutoff
Smaller volume regulation
time
Worse SVR
Smaller mute on/off time
Higher low frequency
cutoff
TYPICAL CHARACTERISTICS: Refer to the Application Circuit of Fig.1 V_S = 21V; RL = 8Ω; f = 1KHz;
RS = 8Ω; Tamb = 25°C; RS = 50Ω; unless otherwise specified
Figure 3: Output Power vs Supply Voltage
Figure 4: Distortion vs Output Power
P_OUT
(W)
14
12
10
8
6
4
2
0
5
D96AU517
d=10%
d=1%
10 15 20 25 30 Vs(V)
d
(%)
D96AU518
V_S=28V
R_L=8Ω
1
f=15KHz
f=1KHz
0.1
0.01
0
2
4
6
8 P_OUT(W)
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