OEM638 Technical Specifications
Appendix E
OEM6 Family Installation and Operation User Manual Rev 12
181
Table 40: 3.3V CMOS Electrical Characteristics (-40 to 85
°
C
)
E.1.2
Power Supply
The OEM638 receiver can operate from either:
•
3.3 V +5%/-3% at up to 2.0 A
or
•
4.5 V to 36 VDC input supply at up to 1.5 A
Power consumption will vary greatly, depending on which features are active.
The OEM638 has integrated reverse voltage protection (to -10 VDC) on its 3.3 V supply input port. The Wide-
Range supply port is reverse protected to -40 VDC.
If operating from the 3.3 V supply input, bulk supply bypassing (approximately 50 uF) and high frequency
bypassing (0.1 uF and 220 pF) near the 3.3 V supply pin is recommended for optimal performance. If
operating from the Wide-Range supply, high-frequency bypassing (0.1 uF and 220 pF) is recommended.
E.1.3
Antenna Power Output
The OEM638 card supplies a software-selectable 3.3 V or 5 V to the center pin of the MMCX RF connector to
power an external antenna (the return is the outer conductor of the coax). There is also the option to provide
an external voltage to the LNA (up to 18 VDC).
This port is capable of providing up to 200 mA to a connected antenna. The typical current draw for a NovAtel
antenna is 25-40 mA.
The internally-generated 3.3 V and 5 V supplies are over current protected. If the external LNA supply is
used, the supply
must
self-limit to 125 mA max to avoid damage to the OEM638 receiver. (There is no over
current protection on the external LNA supply input.)
94 4V5_36V_INPUT
Wide Range
Supply Input
-
-
These pins may connect to an
external wide range supply input. This
is the preferred supply input for the
wide-range supply (see also P4001).
If 4V5_36V_INPUT is used, do
not connect to 3V3_EXT.
96 4V5_36V_INPUT
-
-
98 4V5_36V_INPUT
-
-
100
4V5_36V_INPUT
-
-
Pin
Signal Name
Signal Type
Signal
Direction
Polarity
Drive
Strength
(mA)
Description
The expansion connector on the OEM638 card is
Samtec’s BSH-050-01-L-D-A-TR
. It mates
with
Samtec ASP-166000-01
(this is a semi-custom part from Samtec that provides a mated
height of 14 mm). The standard mating height for the OEM638 card is 14 mm.
Drive Strength
V
IL
V
IH
V
OL
V
OH
R
PULL-UP
R
PULL-DOWN
(mA)
min (V) max (V) min (V) max (V) max (V) min (V)
typ (
Ω
)
typ (
Ω
)
2
-0.3
0.8
2
3.6
0.4
2.4
300
100
4
-0.3
0.8
2
3.6
0.4
2.4
300
100
8
-0.3
0.8
2
3.6
0.4
2.4
150
50