AS3430 datasheet(20/51 Pages) AMSCO

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AS3400 AS3410 AS3430 1v0

Data Sheet - D e t a i l e d D e s c r i p t i o n

Figure 18. I2C Mode Start-Up Sequence

The total start-up time (inlcuding fade-in of the gain stages) can be reduced from 900ms to 600ms by OTP setting.

8.5.3 Mode Switching

When the chip is in stand-alone mode (no I2C control), the mode can be switched with different levels on the MODE pin.

In I2C mode, the monitor mode can be activated be setting the corresponding bit in the system register.

Table 10. Operation Modes

MODE

MODE pin

Description

OFF

LOW (VSS)

Chip is turned off

ANC

HIGH (VBAT)

Chip is turned on and active noise cancellation is active

MONITOR

VBAT/2

Chip is turned on and monitor mode is active

In Monitor mode, a different (normally higher) microphone preamplifier gain can be chosen to get

an amplification of the surrounding noise. This volume can be either fixed or be controlled by the

VOL input.

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.

In addition, the LineIn gain can be lowered to reduce the loudness of the music currently played

back.

AS3430 데이터시트(PDF) 20 Page - ams AG