an7199z Panasonic Corporation of North America, an7199z Datasheet - Page 16

• Manufacturer Part Number: an7199z
• Description: Dual 20 W Btl Power Ic For Car Audio
• Manufacturer: Panasonic Corporation of North America

AN7199Z
16
[2] Application note (continued)
11. Two IC use (continued)
12. Precautions on misuse
Technical Information (continued)
1) Supply terminal
2) Standby terminal (pin 5)
3) Muting terminal (pin 7)
4) Beep sound input terminal (pin 10)
5) Ripple filter terminal (pin 12)
1) Erroneous connection in the case of short-circuit to V
2) Power supply surge
Surge voltage
However, if sufficient characteristics of the ripple rejection can not be obtained, use an even larger capacitor
or insert a 2 200 F capacitor into each IC.
Connect with the microcomputer after connecting the standby pins with each other. At that time, the current
flowing into the standby terminal is twice as large as the current which is described in 1. Standby function.
and 1/2 time respectively, the time constant value becomes as same as the value when one IC is used.
is being applied so that it is difficult to cause the destruction, it is designed so that the mute terminal will
become High when an abnormality such as the short-circuit to V
avoid the influence of IC in an abnormal state when using two ICs).
approx. 12 V at that time.
operation.
In order to avoid such a phenomenon, connect the ICs with each other through a resistor (47 k ).
operation.
circuit after connecting a capacitor (33 F) to each IC.
short-circuit to GND or load short-circuit occur. However, there is a possibility of destruction, then smoke
emission and ignition under a special condition. Avoid misuse and erroneous connection of the circuit.
waveform as shown in figure 11 is evaluated.
Short-circuiting each other, insert an electrolytic capacitor of approx. 2 200 F into the supply terminals.
The best sound quality can be obtained by inserting a 2 200 F capacitor near the terminal of each IC.
Even if the standby terminals are connected with each other, that does not result in an abnormal operation.
An abnormal operation does not occur even if the muting terminals are short-circuited with each other.
The muting time constant changes when two ICs connection is made. If the CR constants are set at twice
In terms of safety design, taking advantage of the fact that a large current is difficult to flow when the mute
Do not connect a microcomputer directly to the mute terminal because the mute terminal voltage rises to
Even if the the beep sound input terminals are short-circuited each other, that does not result in an abnormal
However, if there is a temperature difference between ICs, there may be a fluctuation of the output offset.
Even if the ripple filter terminals are short-circuited each other, that does not result in an abnormal
However, if the standby of each IC is individually controlled, the short-circuiting is not allowed. Use the
The AN7198Z, AN7199Z have the breakdown voltage of 20 V or higher when an short-circuit to V
The power supply surge breakdown voltage is evaluated by the test circuit shown in figure 10 and the surge
The withstanding capability against power supply surge is 80 V for the AN7198Z, AN7199Z.
Figure 10. Power supply surge test circuit
1
(allowance: 1 ) 20 W
D.U.T
CC
and short-circuit to GND or load short-circuit
0.63 V
0.37 V
Figure 11. Surge waveform
CC
0 V
V
ICs for Audio Common Use
or short-circuit to GND takes place. (To
P
P
P
1 ms
6 ms
100 ms
CC
and