User Guide

Iridium Communications Inc. Information Contained in this Guide
9602 SBD Transceiver Product Developers Guide is Subject to Change Without Notice
Revision 1.2 (DRAFT 2)
Iridium Communications Inc. Distribution of Guide Restricted
Proprietary & Confidential Information 22 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 9602/9602N and
ensure that enough current can be drawn across the connector without the 9602/9602N 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 9602/9602N are summarized in Table 9 below. Note that
these requirements apply to DC power measured at the 9602/9602N 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 9602/9602N.
Table 9: DC Power Input Specifications
Parameter 9602 Value 9602N Value
Supply Input Voltage Range 5.0V DC +/-0.5V 5.0V DC +/-0.5V
Supply
Input Voltage Ripple
<
40 mV pp
<
40 mV p
p
Typical Power Consumption at +5.0 VDC 9602 Value 9602N Value
Idle Current (average*) 45mA 35mA
Idle Current (peak) 195mA 170mA
Transmit Current (peak) 1.5 A 1.3A
Transmit Current (average*) 190mA 140mA
Receive Current (peak) 195mA 170mA
Receive Current (average*) 45mA 40mA
SBD message transfer -
average
current*
190 mA 150mA
SBD message transfer -
average
power*
<= 1.0 W <=0.8 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 (9602)/ 1.3A (9602N) 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.