User's Manual

Installation________________________________________________ Boomer-III User Manual & Integrator’s Guide
Copyright Wavenet Technology © October 2003 42 BM310012WT05
Supplying Power
The Boomer-III OEM Modem must be provided with a clean power
source capable of delivering bursts of high current.
The modem draws its power in bursts. The power required changes
rapidly depending on whether the modem is transmitting, receiving or
on standby.
Ratings
The power supply requirements are:
Voltage: 3.8V (3.4 to 4.8V range)
Transmit Current: 1.6A maximum
(2.2A maximum if antenna mismatched)
Transmit Duration: 32ms (minimum)
7s (maximum)
Duty Cycle 30% (maximum) data dependant
Receive Current TBD mA (typical)
Standby Current TBD mA (typical)
Add ~1.2mA if LED’s enabled
Off current consumption: < 20 µA
Power Supply Ripple: < 15mV peak to peak
Design Considerations
The power supply is one of the key issues of design of wireless
terminals.
Due to the burst nature of transmit periods the power supply must be
able to deliver high current peaks for short periods of TBD ms to a
maximum of TBD seconds. During this time the drop in the supply at
the module itself must not exceed 200mV (total at the module), such
that at no time module shall module supply drop below 3.4V and ripple
must not exceed 15mVp-p during transmit.
The maximum transmit current into a matched antenna is 1.6A,
however, this can increase if antenna mismatch occurs.
Wavenet recommends designing a robust power supply that can
provide adequate power under non-ideal conditions such as an
improperly matched antenna, where current can be up to 2.2A.
It is recommended that for ensuring power supply margin the following
be done:
 A short FPC cable (e.g < 100mm) is used to minimise power
supply voltage drop during transmission.
 The power supply should be set above nominal 3.8V to
accommodate worst case power supply drop. i.e. 4.0V.