In the sleep mode all the regulators except the baseband VBB and the SIM card VSIM regulators are off. Sleep mode is activated by the MAD2WD1 after MCU and DSP clocks have been switched off. The voltage regulators for the RF section are switched off and the VCXO power control, VCXOPwr is set low. In this state, only the 32 kHz sleep clock oscillator in CCONT is running. The flash memory power down input is connected to the ExtSysResetX signal, and the flash is deep powered down during the sleep mode.
The sleep mode is exited either by the expiration of a sleep clock counter in the MAD2WD1 or by some external interrupt, generated by a charger connection, key press, headset connection etc. The MAD2WD1 starts the wake up sequence and sets the VCXOPwr and ExtSysResetX control high. AfterVCXO settling-time other regulators and clocks are enabled for active mode. If the battery pack is disconnected during the sleep mode, the CCONT pulls the SIM interface lines low as there is no time to wake up the MCU.
Charging is allowed in any operating mode. For Ni-MH batteries the max. charging temperature is +48°C. Above this temperature the charging algorithm is changed to 'hotcharge' which means that only the amount of current that is taken out from the battery is charged at the same time to the battery.
The battery type/size is indicated by a resistor inside the battery pack. The resistor value corresponds to a specific battery capacity. This capacity value is related to the battery technology as different capacity values are achieved by using different battery technology.
The battery voltage, temperature, size and current are measured by the CCONT controlled by the EM-software (Energy Management) running in the MAD.
The Energy-Management controls the charging current delivered from the charger to the battery. Charging is controlled by a PWM input signal, generated by the CCONT. The PWM pulse width is controlled by the MAD2WD1 and sent to the CCONT through a serial data bus. The battery voltage rise is limited by turning the CHAPS switch off when the battery voltage has reached 5.2V. Charging current is monitored by measuring the voltage drop across a 220 mOhm resistor.
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You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.