NAL A3LA-RG, User Manual

Page: 24 / 180

A3LA-RG Guide Version B
Document Number: 451-93156-009B 24 of 180
2.3 DC P
OWER
I
NPUT
The DC power input is through pins 4 & 16 (EXT_B+) and pins 3 & 17 (EXT_GND). Note that two
pins are provided for the external DC input and two pins are provided for the associated
external ground input. This is done to distribute the current across two wires; therefore, all four
pins should be utilized in the external power connection. Keep cables used to supply power to
the A3LA-RG as short as possible to prevent significant voltage drop, which can cause the A3LA-
RG to malfunction during a data call, an SMS session, or an SBD session. Power reset by the
A3LA-RG during a call indicates the DC power source is unable to sustain voltage above 4.0 V at
peak current demand. Appendix F: Power Consumption provides the electrical power profile of
the A3LA-RG.
The A3LA-RG accepts 4.0 V to +5.4 V or +5.0 V to +32 V input. The A3LA-RG is shipped
with hardware set for +5.0 V to +32 V input. It can be changed to +4.0 V to +5.4 V input through
an internal jumper—POWER MUST BE DISCONNECTED BEFORE RESETING THE JUMPER. Find the
jumper by removing the modem’s bottom plate. With the A3LA-RG held in the position shown
in Figure 3 (DB25 connector to the left), the A3LA-RG is set for 4.0 V to +5.4 V when the red
jumper is on the middle and left pins, and is set for +5.0 V to +32 V when the jumper is on the
middle and right pins. Each pin is also labeled with 5 V and 32 V to the left and right pins,
respectively.
Note : User MUST remember the input voltage setting on the A3LA-RG and not to apply voltage
above the maximum limit (of either 5.4 V or 32 V). The A3LA-RG will be damaged beyond repair
with warranty voided if this were to occur.
Figure 3: Power Input Setting for the A3LA-RG
Red jumper used
to set input
voltage range