http://cxema.ru
POWER SUPPLIES
Issue 1
Section 9
MCUK990801G8
Revision 0
– 38 –
Technical Guide
D1V8 : Power supply for GEMINI process version 1833C07 (ARM, DSP and ASIC)
Voltage
1.8 V ± 3 %
Current
120 mA max.
A2V8 : Baseband power supply for Analogue circuitry (VEGA and Voice-Memo)
Voltage
2.8 V ± 3 %
Current
100 mA max.
Dropout:
same as D2V8
SIM5V : SIM power supply (SIM & GEMINI/SIM interface)
Voltage
5.0 V ± 5 %
Current
50 mA max.
EXT_PWR : Power supply for battery charger
Voltage
5.8 V ± 0.2 V
Current
720 mA ± 30 mA
2V5 :VSRF, voltage supply for RF circuit, only turned on when LO_EN signal is high
2V5 :VS_VCO, voltage supply for VCO, only turned on when LO_EN signal is high
2V5 :VS_VXCO, voltage supply for RF circuit, only turned on when RF_ON signal is high
9.5.5 Battery Charging & Monitoring
The status of the LCD battery icon is determined by the value of BAT_VOLT returned from VEGA, the battery ICON has four
states.
The battery charging is controlled by the CPU within the phone. If rechargeable cells are detected and the temperature is within
specified limits the charger starts a rapid charge algorithm.
When the battery is NiMH, charging is determined by -
δ
V with time, temperature and voltage safe-guards. When the battery is
Li+ or Li-polymer, charging is determined by constant current and constant current voltage with time, temperature, current and
voltage safe-guards. A current limit no greater than the maximum charge current for any battery option must be provided by
the external power source.
In the case of deeply discharged batteries there may not be enough power in the battery to initiate a charge. Therefore, the
charging circuit must automatically start to trickle charge until there is enough power to switch on the phone.
