User Guide

Figure 74 RM-86 keyboard matrix

Backlights

There are four white LEDs for numeric keyboard backlight and a red, white and yellow-green LED for mode

key backlight.

The display includes four white LEDs for display backlights inside of the display module. Voltage source for

backlights is implemented using an external white LED driver.

ASICs

RAPGSM ASIC

RAPGSM is a GSM EDGE chip.

Retu EM ASIC N2200

EM ASIC N2200 includes various control functions.

Tahvo EM ASIC (N2300)

Tahvo EM ASIC (N2300) is intended for energy management control, supply voltage generation and charge

control of mobile phone.

Device memories

RAPGSM memories NOR flash and SDRAM

Modem memory consists of 256Mbit SDRAM and 512Mbit NOR flash memory.

Audio concept

Audio HW architecture

The functional core of the audio hardware is built around two ASICs: RAPGSM engine ASIC and the mixed-

signal ASIC Retu.

Retu provides an interface for the transducers and the accessory connector. Integrated hands free stereo

spekers are driven by a D-class audio amplifier TPA2012D2.

There are four audio transducers:

• 8 mm dynamic earpiece

• 20 mm dynamic speaker

• electret 4x1.5 mm microphone

In addition to the audio transducers, Retu also provides an output for the dynamic vibra component.

RM-86

Nokia Customer Care System Module

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