Multi Band - Sony CMD-MZ5 Service Manual

SECTION 2
GENERAL DESCRIPTIONS
2.1 Multi-band :
CMD-MZ5 support E-GSM 900 and DCS 1800 multi-band functionality.
Because the usage of multi-band depends on network capabilities, the phone is able to operate as a single band
mobile in GSM 900 as well as in DCS 1800; In addition, it supports the extra functionality required for multi-band
mobile stations: Inter-band/"seamless" hand-over, channel assignment, cell selection and re-selection, all between
both bands within a Public Land Mobile Network.
The manual and automatic PLMN selection in both bands is given.
The user does not need any special action to use the multi-band functionality of the phone.
Users are able to manually roam between PLMN's operating in GSM 900 and DCS 1800 bands.
The CMD-MZ5 is a phase II, GSM 900 class 4, DCS 1800 class 1 mobile phone.
The nominal maximum output power for GSM 900 is 2W, for DCS 1800 1W.
2.2 Real Time Clock (RTC)
The real time clock is integrated into phone.
When the mobile is switched on the RTC is powered via the CPP.
When the phone is powered down, the RTC is powered from the main battery via its own low quiescent current
regulator.
When the main battery is low or removed, a back-up battery keeps the clock alive.
2.3 Vibra Alert Functionality
The vibrator is a 1.3V device.
A general port pin of the SC1 controls the switch mode of the vibration motor. It is powered through a regulator by
an interface control unit. If the mobile is in the phase of switching on or off the vibrator is off at all times.
2.4 Battery Safety
The battery pack contains a safety circuitry. The charging circuitry and the safety circuitry together guarantee a
double fail-safe battery pack. This means that each component can be either short or open and still all the safety
requirements will not be violated.
The safety concept protects against:
Over voltage: The charging is stopped when Battery Voltage (Vbat) reaches 4.24V- 4.3V. The charging resumes
when Vbat falls below 4.06V - 4.15V.
Under voltage: When the cell voltage drops below 2.5V - 2.7V the cell is disconnected for discharging.
Charging is still possible.
2.5 Battery Charging
Standard Battery 620mAh typical Li-ion 1-476-508-11
The phone can be charged even during making phone calls.
However, the shortest charging time will be reached when the phone is switched off.
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