Boomer-III User Manual & Integrator’s Guide_________________________________________________Installation
BM310012WT04
31
Copyright Wavenet Technology © October 2003
Warning: When the modem is turned off using the HOSTPWR_ON
signal and HOST_3.8V power is removed, all other signals connected
to the Data Interface Connector should also be turned off or set to 0V
otherwise the modem may remain powered on via these signals.
Real Time Clock Battery Backup
The Boomer-III contains an on-board Real Time Clock (RTC) and the
RTC Battery Backup (RTC_BB) pin is an optional input to maintain
the clock settings (time and date) in the event the main power to the
modem is removed. If used this input must be connected to a stable
voltage supply (such as a suitable alkaline cell) that does not exceed the
maximum input voltage specifications. If not required this input can be
left disconnected and the RTC will be powered internally. The
electrical interface specification and equivalent circuit is as follows:
Real Time Clock Equivalent Circuit
Real Time Clock Electrical Characteristics
Parameter Range
Min Max
Input Voltage
2.1 V
3V (max)
Input Current
1 µA
10 µA
Warning: The input voltage on RTC-BB (pin 11) must never exceed 3V
under any circumstances or the modem may be damaged.