Topaz T2688/T200, T2988/T205 L3 Circuit Description
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Motorola Proprietary Information
These are:
? Power on generated by set alarm, which is generated from the RTC (the alarm
is set into the menu structure of the phone). U54 Pin 2
? IO2, software originated power on from Gemini Pin 112. U54 Pin 1
? From depressing the Power On key giving the signal PWR. U53 Pin 2
? From the External Charger (CHGERP). U53 Pin 1
77. As the unit begins to power up the reset signal is generated, again a +ve going signal.
Charging C57 generates the charge for the reset signal.
78. As for the GCAP the Power Control IC also interfaces with the SIM Card, VCC for
the SIM card is provided by Pin 20, onto SIM Block Pins 4 & 5. However the
occasional need for 5V SIM is provided using the input from the scaled DVCC on
Pin 17 and the charge pump C53 Pins 21 & 9.
79. Data is read from the SIM card on pin 2 of the SIM block I/O into U27 Pin 15 (IO)
and transmitted to the Gemini from U27 Pin 11 (S-IO). Also from Gemini are the
SIM CLK U27 Pin 13[in] & Pin 19 [out] (SIM Block Pin 1) and the SIM Reset U27
Pin 12 [in] and Pin 16 [out] (SIM Block Pin 3)
80. SIM I/O also acts as a SIM Presence detect signal.
81. Power for the unit can be taken from either internal Battery or from an external
source. The battery has 4 contacts, from battery connector JP2
? Pin 1 Supplies VBAT directly
? Pin 2 BATEMP is used to monitor Battery temperature during charging, and is
fed to VEGA for A / D processing.
? Pin 3 BAID is Battery ID and is used for the detection of different types of
batteries.
? Pin4 is ground
Alternatively the VBAT source can be taken from an external power source, this
originates at the I/O connector U40 Pin A3, with U36 providing ESD protection, the
signal is then fed as CHGERP, and through Fuse F1. As mentioned in Point 76 this
will ensure the unit powers up but will also pass through BQ3 and protection diode
D14 to provide VBAT. D15 limits input voltage to <6V
82. U30 is used to detect the charger and is supported by DVCC, once detected an
interrupt is sent to Gemini as IO9
83. For the Initial charge at low battery voltage, as before the input voltage at CHGERP
is approximately 6V,CHGERP originates at U40 Pin T3 with T1 as its respective
Ground
84. NOTE: If a desktop charger then I06 is used to communicate to the Gemini the status
of the charging indicator on the charger.
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