User Guide

Internal microphone

The internal microphone is used for HandPortable (HP) and Internal HandsFree (IHF) call modes.

A digital MEMS microphone data and clock line are connected to Rapido ASIC while power supply is received

from Avilma.

Figure 55 Internal microphone circuitry

External microphone and earpiece

Galvanic accessories are connected to the AV connector. Accessory audio mode is automatically enabled /

disabled during connection/disconnection of dedicated phone accessories.

External microphone circuitry is biased by Avilma ASIC MicB2 bias voltage output. The circuitry provides an

asymmetrical connection for the microphone from the AV connector, XMICP to Avilma ASIC input, mic2p and

XMICN, to GND.

The Avilma ASIC provides two output channels in either single-ended or differential format. The Avilma ASIC

outputs XearL and XearLC form the left channel audio output and XearR and XearRC the right channel audio

output. XearLC and XearRC are the ground pins if the output works in a single-ended operation.

RM-244

System Module and User Interface

Issue 1 COMPANY CONFIDENTIAL Page 6 –23