Section 2, General descriptions, 1 multi-band – Sony CMD-CD18 User Manual
Page 5: 2 real time clock (rtc), 3 vibra functionality, 4 battery safety, 1 multi band, 2 real time clock 2.3 vibra alert functionality, The real time clock is integrated into the phone
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SECTION 2
GENERAL DESCRIPTIONS
2.1 Multi-band :
CMD-CD18 support E-GSM 900 and DCS 1800 multi-band functionality.
Because
the
usage
of
multi-band
depends
on
network
capabilities,
the
phone
is
able
to
operate
as
a
single
band
mobile
in
GSM
900
as
weil
as
in
DCS
1800;
In
addition
it
supports
the
extra
functionality
required
for
multi-band
mobile
stations:
lnter-band/”seamless”
hand-over,
channel
assignment,
cell
selection
and
re-selection,
all
between
both bands within a Public Land Mobile Network.
The manual and automatic PLMN selection in both bands is given.
The user does not need any special action to use the multi-band functionality of the phone.
Users are able to manually roam between PLMN’s operating in GSM 900 and DCS 1800 bands.
The CMD-CD18 is a phase II, GSM 900 class 4, DCS 1800 class 1 mobile phone.
The nominal maximum output power for GSM 900 is 2W, for DCS 1800 1W.
2.2 Real Time Clock (RTC):
The real time clock is integrated into the phone.
When the mobile is switched on the RTC is powered via the CPU.
When
the
phone
is
powered
down,
the
RTC
is
powered
from
the
main
battery
via
it’s
own
low
quiescent
current
regulator.
When the main battery is low or removed, a back-up battery keeps the clock alive.
After the main battery has reached a voltage level of 3.5V the RTC keeps the time for 10 days.
After the main battery is removed the RTC keeps the time for 10 min.
2.3 Vibra Functionality
The vibrator is a 1.3V device with a vibrating frequency fixed at 120Hz (±20%) and located in the handset.
A
general
port
pin
of
the
CPU
controls
the
switch
mode
of
the
vibration
motor.
It
is
powered
directly
from
the
battery by an interface control unit. If the mobile is in the phase of switching on or off the vibrator is off at ail times.
2.4 Battery Safety
The
battery
pack
contains
a
safety
circuitry.
The
charging
circuitry
and
the
safety
circuitry
together
guarantee
a
double
fail-safe
battery
pack.
This
means
that
each
component
can
be
either
short
or
open
and
still
all
the
safety
requirements will not be violated.
The safety concept protects against:
Over
voltage:
The
charging
is
stopped
when
Battery
Voltage
(Vbat)
reaches
(4.24V-
4.3V).
The
charging
resumes
when Vbat falls below (4.1 IV - 4.23V).
Under voltage: When the cell voltage drops below (1.3V - 1.7V) the cell is disconnected for discharging.
Charging is still possible.