AN7195 Panasonic Semiconductor, AN7195 Datasheet - Page 10

• Manufacturer Part Number: AN7195
• Description: Dual 15 W BTL power IC for car audio
• Manufacturer: Panasonic Semiconductor

AN7195K
10
[2] Application note (continued)
8. Mute Function
9. Voltage gain
Technical Information (continued)
V
1) The mute-on/off is possible by making pin 7 (the muting terminal) high or low.
2) The muting circuit is as shown in figure 6. The amplifier gain including attenuator block is given in the
3) The threshold voltage of V
4) Attack time and recovery time can be changed by the external CR of pin 7. For recommended circuits (In
5) When the attack time and recovery time are set at 20 ms or less, pay attention to the IC with larger output
MUTE
following equation :
figure 6 4.7 k ,10 F), the above mentioned times are as follows :
microcomputer (5 V), (that is, 13.2 V separate power supply), it is necessary to change CR values because the
above times change.
offset because it may release the shock noise.
5 V
0 V
G
From the above equation, the amplifier gain can be made as 0 time by setting I
Mute-off : approx. 1 V or less
Mute-on : approx. 3 V or more
Attack time
Recovery time : Approx. 40 ms
However, the control voltage of V
The voltage gain is fixed at 40 dB and can not be changed by the addition of an external resistor.
V
Mute/off
Mute/on
I
I
1
2
50
4.7 k
: Approx. 30 ms
10 F
Original gain
MUTE
Input
is as follows :
7
MUTE
5 k
is assumed to be 5 V. When it is not directly controlled by
Figure 6
ICs for Audio Common Use
Attenuator block
I
I
1
1
I
I
1
2
1
at 0 mA at muting.
approx.120 A
approx.120 A
I
I
2
2
Output stage
Output stage