Iridium Communications Inc.
Information Contained in this Guide
9602 SBD Transceiver Product Developers Guide is Subject to Change Without Notice
Revision 4.0
Iridium Communications Inc.
Distribution of Guide Restricted
Proprietary & Confidential Information 19 to Product Developers Only
3.2 DC Power Interface
The DC power interface is comprised of the DC power inputs and a control signals as summarized in
Table 7. The +5V Inputs and 0V supply returns are used to supply DC power to the 9602 and ensure that
enough current can be drawn across the connector without the 9602 malfunctioning during transmit due
to lack of current supply. Note that all power and ground pins should be connected externally.
The DC power supply requirements for the 9602 are summarized in Table 9 below. Note that these
requirements apply to DC power measured at the 9602 User connector input and not at the output of the
power supply. Long power supply cables can cause a voltage drop sufficient to cause the voltage to be
out of specification at the physical power supply input to the 9602.
Table 9: DC Power Input Specifications
Parameter
Value
Supply Input Voltage Range
5.0V DC +/-0.5V
Supply Input Voltage Ripple
< 40 mV pp
Typical Power Consumption at +5.0 VDC
Value
Idle Current (average*)
45mA
Idle Current (peak)
195mA
Transmit Current (peak)
1.5 A
Transmit Current (average*)
190mA
Receive Current (peak)
195mA
Receive Current (average*)
45mA
SBD message transfer - average current*
190 mA
SBD message transfer - average power*
<= 1.0 W
* Note: The average power consumption will vary depending on the view of the satellite constellation from
the antenna.
The external power supply needs to
guarantee
the following:
The supply voltage droop over for a 8.3ms burst of 1.5A current should not be more than 0.2 Volts.
The power supply should limit the in-rush
2
current to 4 Amps maximum
The power source shall provide for over current protection in case of device malfunction.
The supply noise should be less than the limits in the following profile:
100 mVpp
from 0 to 50 kHz
5 mVpp
at 1 MHz measured in 50 kHz bandwidth
10 mVpp
at 1 MHz measured in 1MHz bandwidth
5 mVpp
above 5 MHz measured in 1 MHz bandwidth.
2
In rush limit refers to the impedance of the modem when it is unpowered is very low. When power is supplied
from an unlimited supply the instantaneous current can exceed 4 Amps If the current exceeds this value damage can
occur. This can be limited in several ways, included using a supply that cannot provide more than 4 Amps
instantaneously; or providing some series inductance/resistance to the supply lead.
