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AS3418

Functional Description

Datasheet

• PUBLIC

DS000507

• v4-00 • 2020-Jan-23

│ 34

MODE

Description

MONITOR

In Monitor Mode, a different (normally higher) microphone preamplifier gain can be

configured to get an amplification of the ambient noise. To get rid of the low pass

filtering needed for the noise cancellation, the headphone input multiplexer can be

set to a different (normally to MIC) source to increase speech intelligibility. In

addition, the Line Input signal can be muted for further improved intelligibility. If the

device is operated in I2C mode, it is also possible to enter the monitor mode by

setting the MON_MODE_EN bit in register 0x03.

PBO

The Playback Only mode is a special mode that disables the noise cancelling

function and just keeps e.g. line input amplifier or headphone amplifier active.

Certainly this operation mode can also be used as an alternative Monitor or ANC

mode with different gain settings.

With the AS3418 design engineers have different options to enter the described operation modes

shown in Figure 41. In addition to the different user interface modes described in the following three

chapters, it is also important to configure the device accordingly. Figure 42 shows the required register

configuration settings to enable the different AS3418 control modes.

Figure 42:

User Interface Control Modes

MODE

Button Mode

Slider Mode

Full Slider Mode

Do not use

6.8.1

Full Slider Mode

Full Slider Mode enables the AS3418 to be connected to two slide switches for Power, ANC and

Monitor Mode control. To enable this operation mode register UI_MODE

has to be set to ‘d2’. The

typical connection of the slide switches is shown in Figure 43.

AS3418 Datasheet(PDF) 34 Page - ams AG