la4814v Sanyo Semiconductor Corporation, la4814v Datasheet - Page 7

• Manufacturer Part Number: la4814v
• Description: 2-channel Power Amplifier
• Manufacturer: Sanyo Semiconductor Corporation

9.Turn-off transient response characteristics
If the IC is turned off and then turned back on while there is a potential difference between the pin 7 (reference voltage,
plus input pin) and pins 5 and 10 (minus input pins), a louder pop noise than the one normally generated when power is
switched on will be emitted. Therefore, in order to minimize the turn-on pop noise, smoothen the discharge of the input
and output capacitors, and bring the potential of pin 7 and pins 5 and 10 to approximately the same level, then turn on
the IC.
a) Single ended mode
b) BTL mode
When the continuous changeover of mode between standby and operation is necessary, it is recommended to insert a
resistor between the output pins (pins 3 and 12) and ground to accelerate the turn-off transient response characteristic.
The value shown below is recommended for the resistor used for discharge. In order to reduce pop noise, it is
recommended that time necessary for turning the IC back on is greater than the following value.
When the continuous changeover of mode between standby and operation is performed, it is recommended that the
second amplifier control function be used to reduce the turn-on pop noise. If this function is used, the pop noise level
can be reduced regardless of the time taken for the IC to turn on after it is turned off.
For details on the time taken for the second amplifier to turn on after the IC is turned on, refer to Section 5 “Second
amplifier control function.”
PWR → STBY
OUT:50mV/div,AC
7pin:1V/div,DC
T
STBY → PWR
Recommended discharge resistor : R = 4.7kΩ
(Recommended turn-on time : T = 600ms)
100ms/div
LA4814V
4.7kΩ
+
R1 10kΩ
C1 0.22μF
3
5
OUT1
IN1
10kΩ
+
-
No.A0972-7/17
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