Power Supply Concept; Over Voltage Condition - Siemens M35 Series Service Manual

Power Supply Concept

The M35i has two main power inputs:
1. Battery voltage(3.6V) connected at the battery contact
2. Charging voltage(6.5V) delivered by the different charger type(see Accessory List) via the
Lumberg connector at the bottom of the telephone.
Since the battery voltage is supplying the power supply ASIC, it is always needed to operate the
phone. You cannot switch on the handset if the battery voltage is not present.
From the battery voltage, all other supply voltages are derived and controlled by the power
supply ASIC.
The RF power amplifier is directly connect to the battery, a bad battery with high internal
resistance can cause malfunction of the M35i phone.
The Logic module uses 1.92V, 2.65V & 2.9V generated by voltage regulators inside the ASIC.
Furthermore, the ASIC generates the supply voltage for the SIM card and the RESET signal for
the logic devices.
The ASIC also checks the presence of the watchdog signal from the microprocessor and
provides the switching on functionality (ON_OFF button or Ignition signal).

Over-voltage Condition
•
Battery voltage
If the supply voltage rises above 6.2V, the phone will switch off and it cannot be switched on
again before the voltage is lower than 6.2V. If the supply voltage rises above 7V, the phone
can be damaged
•
Charging Current
The charging current must not rise above 1A or a track fuse in the phone will blow. As a
result charging the battery will no longer by possible.

Wrong polarity or battery voltage setting that exceed the +6.5V
Be careful with NON-original SIEMENS accessories or chargers.
Make sure that the charging current is limited to value below 1A.
could damage the phone.