ORBCOMM OG2 Modem Integration Manual
18
Receive Mode:
100 mA @ 12VDC
The graph below show the maximum current (transmit mode) requirements over a range of input
voltages. Per integration requirements 6 VDC is the minimum operational voltage.
Figure 4-1 Maximum Input Current vs Input Voltage
4.2
Variations in Input Power
The power supply is a buck-boost configuration and can operate between 4.0 VDC and 15 VDC. A
full RF output requires an input voltage above the minimum operating voltage. The system will
control the switcher to run in a high efficiency burst mode and provide the required PWM mode to
satisfy high demand events. The circuit is short-circuit protected, has a soft start feature, provides
current limiting, and a thermal shutdown feature.
The diagram below shows voltage rise time for the processor (gray), receiver (pink), and power
amplifier (blue) with a 4.0 VDC input voltage. The delay from power-on to processor operation is
1.3 ms. The other voltages are controlled internally by the processor and do not operate until the
I/O ports are functional and a message has been queued by the user.
The pink line indicates the rise time of the receiver section.
The blue line indicates the rise time of the transmitter section, current draw is increased to
maximum levels approximately 15 ms after this ramp up time.
0.0
1.0
2.0
3.0
4.0
5.0
6.0
M
ax
imu
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Inp
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(
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)
Input Voltage (DC)
Maximum Input Current vs Input Voltage
