V1.0 Page 27 of 46 ICM MP CCQ ST
C45, M50 AND MT50 Company Confidential © Copyright Siemens AG 05/02
For temperature detection, a NTC resistor (22kΩ at 25°) is assembled in the
battery pack. Via the pin 2 of the battery connector connected to the
EGOLD+ (GAIM L3) is carrying out the measurement.
The voltage is measured from the GAIM-part of the EGOLD+ (see description
In chapter 7)
Trickle charge
If the phone has not been used for a longish time (longer than approx. 1 month), the
battery could be totally self-discharged. (battery voltage less then 3,2V), so that
it is not possible to charge the battery via the normal charging circuit. In this case
only trickle charge is possible.
The STV-ASIC (D361) controls the charging circuit himself.
- Battery voltage below 2,8 Volt charging current 20mA.
- Battery voltage below 3,2 Volt charging current 50mA.
- Battery voltage over 3,2 Volt “Normal charging”.
Power supply for the ASIC (D361) in this mode is the external charger.
(VDD_CHARGE)
The switch into normal charging mode, is done automatically if the required voltage
is reached.
Trickle Charging Power Supply
“Normal/Trickle” charging activation
!! Attention!!
- a charger voltage >15V can destroy resistors or capacitors in the charging path
- a charger voltage >20V can destroy the MOS-FET switch transistor in the
charging path.
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