Benefon Twin, Service Manual

Page: 24 / 53

08.02.2002
9gp_71gb.fm 4
Product: TGP71EU & TGP73EU /
If this signal has been pulled to ground and the headset detector (pin 7)
is in logic ’1’ state the mobile assumes that there is an accessory using
serial port connected to the system connector.
PIN 14 & 15: Asynchronic serial line number 2 (RS232) for accessories and for
debugging mobile’s software. This line does not have CTS or RTS
signals. The data is transferred according EMMI protocol defined in
GSM phase2 specification 11.10-1 section 36.3.5.; 9600 bit/s, 1 start bit
(S), 8 bits (D1 to D8), no parity, 1 stopbit (E). The flow control is not
used.
NMEA 0183 signals for GPS phones
PIN 16: The maximum current of DGND pin is 1,0A.
PIN 17: Not connected. If connected, Charger Switch 0 (CHGSW0) is normally
in logic ‘1’ state (2.7V) and grounded when the charger is connected to
DC jack.
PIN 18: Same as pin 16. The maximum current of DGND pin is 1.0A.
PIN 19: Not connected. If connected, Charger Switch 1 (CHGSW1) is normally
grounded and goes to logic ‘1’ state when the charger is connected to
DC jack.
PIN 20: Same as pin 6. The maximum current of CHARGE pin is 1.0A.
The maximum current of all pins except pins 6, 9 and 16 - 20 is 10 mA.
5.0.4 Charging & battery
During charging the charger provides a constant current that can be cut off by the
phone. After main charging phase phone uses short current pulses to keep up the
fully charged. Charging connector uses only two leads and therefore the charging
cable and connector can be simple.
The estimate of remaining battery capacity is based on both battery voltage and
used current integration. Current integration means that phone makes “notes” on the
current used and the period this current was used.
TG charging concept has charger options. Slow “overnight” charger and fast
charger.
TG battery concept uses to pins to read battery type. The pins can only have fixed
setting, low (ground) and high. This limits the number of battery categories to four.
Note that within a category the battery capacity can vary up to 10-15%, but the cell
type remains the same.