Als Interface; Asics; Rap Asic; Em Asic N2200 - Nokia RM-132 Service Manual & Parts Manual

RM-132; RM-133
System Module Nokia Customer Care

ALS interface

Ambient Light Sensor (ALS) is located in the upper part of the phone. It consists of the following components:
• lightguide (part of the front cover)
• phototransistor (V6501) + resistor (R4401)
• NTC + resistors (R4400, R4402, R4403)
• Common mode filter (L7551)
• EM ASIC (N2200)
Information on ambient lighting is used to control the backlights of the phone:
• Keypad lighting is switched on only when the environment is dark
• Display backlights are dimmed, when the environment is dark
The ambient light sensor itself is a photo transistor, which is temperature-compensated by an external NTC
resistor. The EM ASIC N2200 reads the light sensor (LS) and temperature (LST) results.
ALS calibration is not possible in the service points. ALS is serviced by replacing faulty phototransistors.

ASICs

RAP ASIC

RAP ASIC is a 3G Radio Application Processor. RAM memory is integrated into RAP.

EM ASIC N2200

The EM ASIC (N2200) includes the following functional blocks:
• Start up logic and reset control
• Charger detection
• Battery voltage monitoring
• 32.768kHz clock with external crystal
• Real time clock with external backup battery
• SIM card interface
• Stereo audio codecs and amplifiers
• A/D converter
• Regulators
• Vibra interface
• Digital interface (CBUS)

EM ASIC N2300

The EM ASIC (N2300) includes the following functional blocks:
• Core supply generation
• Charge control circuitry
• Level shifter and regulator for USB/FBUS
• Current gauge for battery current measuring
• LED driver for backlights
• Digital interface (CBUS)
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