
Private Communication Systems
Mobile Phones
Furthermore the ASIC generates the supply voltage for the SIM-Card and the
RESET signal for the logic devices.
The ASIC also checks the presence of the watchdog signal from the µP and provides
the switching on functionality (ON_OFF button or Ignition signal).
During testing ist is advisable to use a battery dummy, connected to a power supply
deli4V, max 3A.
Make sure that you connect the battery dummy with the right polarity, the red plug to
+4V and the blue plug to ground.
If you use a voltage higher than +7V, or with wrong polarity, the phone can be
destroyed!
4.4Critical Conditions
a) Battery Voltage:
If the battery voltages rises above 6.2 Volts, the phone will switch off and it cannot
be switched on again before the voltage drops below 6.2 Volts.
If the battery voltage rises above 7 Volts the phone can be destroyed.
b) Battery Charging Current:
The charging current must not rise above 1 A or the phone (fuse) will be inoperable.
-> Be careful with foreign accessories or chargers!
-> Make sure that the charging current is limited to a value
below 1A!
c) Supply Current for External Accessories:
If you use accessories that are supplied through the bottom connector of the
handset, make sure that the accessory does not draw more than 250 mA.
Otherwise a 0.25 A fuse will blow.
5Software programming
The software of the S11 handsets is programmed directly from a PC using the
bootadapter (see drawing below).
V1.1
13
PN MP ST
D. Schnoor
04/98