LA4708 查看數據表（PDF） - SANYO -> Panasonic
零件编号
产品描述 (功能)
生产厂家
LA4708 Datasheet PDF : 9 Pages
| |||
LA4708
Features of IC Inside and Usage Notes
Standby function
. Pin 5 is the standby switch pin. The amplifier is turned on by applying approximately 2.5 V or more to this pin through an
. external resistor (R1).
If voltage in excess of 13.2 V is to be applied to the standby switch, calculate the value of R1 using the following formula so
that the current flowing into pin 5 is 500 µA or less:
Applied voltage − 1.4 V
R1 =
500 µA
– 10 kΩ
500 µA or less
Pin 5 Equivalent
circuit internal IC
Standby
About 1.4 V
applied voltage (2VBE)
Mute function
. Pin 6 is the connector for the capacitor that determines the on time in order to prevent pop noise. By grounding this pin, the
amplifier can implement mute operation. In this case, the recovery time depends on C3.
How to reduce pop noise
. Although the LA4708 reduces pop noise, an electrolytic capacitor of between 0.47 and 2.2 µF can be connected between pin 8
and the pre-GND to further reduce pop noise that occurs when power supply is turned on/off (standby switch on/off). The larger
the capacitance, the lower the frequency of pop noise, and it is barely audible, but sound residue of the sound signal is liable to
linger when power is turned off. Pin 8 is the bias pin for the output amplifier and normally is left open.
Protectors
. In an output-to-ground and output-to-VCC short protector system configuration, if a DC resistor is connected between amplifier
output pin and GND, the protector may operate, causing the amplifier not to start operating. Therefore, as a general rule, no DC
. resistor should be connected between amplifier output pin and GND.
In order to prevent damage or degradation which may be caused by abnormally heated IC, the LA4708 has a thermal shutdown
protector. Accordingly, if the IC junction temperature (Tj) climbs to around 170 to 180°C due to inadequate heat dissipation, the
. thermal shutdown protector will operate to control the output gradually into attenuation.
Also be fully careful of handling other protectors built in the LA4708.
Miscellaneous
. Since pins 1 and 9, which are unused, are connected internally, they must be left open.
. Pin 10 is an NC pin (no internal connection).
No.5245 -5/9
Share Link: 