Table 2–3
Power connector: J8
Pin Function Function Pin
1
nc nc 6
2 GND
+5v
7
3 GND
+5v
8
4 +12V –12V
9
5 +3V
GND
10
XE–800 SBC power supply requirements
The XE–800 SBC is designed to operate from a 5 VDC supply, connected at
J8. The connector is a 10-pin ATX PC power supply connector, and connects to a
10-pin ATX power supply, or with an adapter cable, to a standard 20-pin ATX
power supply. The typical current requirement for the XE–800 SBC is listed in the
Technical Data
appendix. If you are using the PC/104 or PC/104
Plus
interface, you
may also require
±
12 VDC and/or +3V.
The user should consider factors such as the power cable conductor gauge, number
and length of conductors, mating connectors, and the power requirements of
external devices such as hard drives, floppy drives, displays, mouse, and keyboard.
It is important that a quality power supply be used that has sufficient current
capacity, line and load regulation, hold up time, current limiting, and minimum
ripple.
The power supply for the XE–800 must meet the startup risetime requirements
specified in the ATX Power Design Guide, version 1.1, section 3.3.5. This assures
that all the circuitry on the XE–800 sequences properly and avoids system lockup.
Also, select a power supply that discharges quickly. If large power supply output
capacitors are used, powering the system down and then up may lock up the XE–
800 SBC. If the power supply does not drain below 0.7V, the CMOS components on
the XE–800 SBC will act like diodes and forward bias, potentially damaging the
XE–800 SBC circuitry.
The proper selection of a quality power supply ensures reliability and proper
functioning of the XE–800 SBC.
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