User Guide

Nokia Customer Care System Module

Company Confidential RH-30/RH-31

Figure 28: Flashlight.

Internal earpiece

Internal earpiece is a dynamic leak tolerant type earpiece with an impedance of 32Ohms.

The earpiece is a low impedance one since the sound pressure is to be generated using

current and not voltage as supply voltage is restricted to 2.7V. The earpiece is driven dif-

ferentially directly by UEM. Earpiece capsule is mounted in LCD frame assembly.

IHF

Integrated Hands Free Speaker, 16mm MALT, is used to generate speech audio, ringing

and alerting tones in RH-30/RH-31. Nominal impedance of the speaker is 8 Ohms. IHF

speaker is driven by a stereo audio amplifier. Audio amplifier is controlled by UPP.

Speaker capsule is mounted in C-cover assembly. Spring contacts are used to connect the

IHF Speaker contacts to the main PWB.

Internal microphone

The internal microphone capsule is mounted in the UI-frame. Microphone is omnidirec-

tional and it is connected to UEM microphone input MIC1P/N. The microphone input is

asymmetric and the UEM (MICB1) provides the bias voltage. Nominal impedance of the

microphone is 1.8kOhms. The microphone input to UEM is ESD protected. Spring con-

tacts are used to connect the microphone to the main PWB. Microphone is mounted in

LCD frame assembly.

IR module

The IR interface in case of transceiver with 1.8V I/O voltage is designed into UPP. The IR

link supports transmission speeds from 9600 bit/s to 1.152 MBit/s up to distance of 80

cm. Transmission over the IR if half-duplex.

The length of the transmitted IR pulse depends on the speed of the transmission. When