LA4820M Просмотр технического описания (PDF) - SANYO -> Panasonic

Номер в каталоге

Компоненты Описание

производитель

LA4820M

Monaural Speaker/Stereo Headphone Power Amplifier

SANYO -> Panasonic 

LA4820M

c An equivalent circuit for the mute circuit is shown on the previous page. If the power supply is turned on, the external capacitor

is charged by the internal constant current; once the voltage reaches 0.75 V (the switching level), mute turns off and the pin 2

DC voltage stabilizes at approximately 1.2 V. To turn mute on, short through a resistor to pull down pin 2. In this way,

smoothing is applied by using an external capacitor and resistor to prevent switching noise when mute is turned on/off.

c The mute-on/off time during normal operation is as shown below.

When 270 kΩ and 0.033 µF are used:

Mute off

Pin 2 charging

Mute on

Pin 2 discharging

Mute-off time 6 8 ms

Mute-on time 6 9 ms

2. Common amplifier control switch

c When the headphone output is connected to other equipment, in an application set in which the common amplifier output (jack

common pin) may be connected to GND causing overcurrent to flow from the common amplifier, it is necessary to turn off the

common amplifier. In such an application, it is recommended to use the common capacitor scheme shown in Sample Application

Circuit 2 where pin 11 is grounded to turn off the common amplifier.

c An equivalent circuit for the switching circuit is shown below.

c PWRC-off condition VS11 % 0.4 V

3. HzP/SP switch

c This circuit uses a headphone jack with a switch to detect the headphone plug-in/out and automatically switch between the HzP

amplifier and the MONO amplifier. When the HzP amplifier is operating, the MONO amplifier is turned off, and when the

MONO amplifier is operating, the HzP amplifier is turned off.

c Smoothing is applied by using an external capacitor and resistor in order to prevent switching shock noise.

c Open HzP condition

VS14 % 0.2 V

to

No.5205-14/20

Share Link: