GL815E Endura Motherboard Product Manual
Page 29 of 51
3.8.2 Power Supply Selection
The GL8"5E motherboard is designed to operate in conjunction with an ATX compatible power
supply, as defined in section 4.2 of the ATX 2.03 specification. The provision of a 5V standby power
rail is optional but, if not provided, the soft-switched power supply control features of the
motherboard cannot be used. Where the standby rail is provided, ensure it is capable of providing
sufficient current for the motherboard, particularly when the optional motherboard LAN controller is
fitted or a PCI adapter card that draws current from the auxiliary 3.3V supply is used.
The tolerances on the voltage rails are described in the ATX specification 2.03 section 4.2.3 and
reproduced below. The -5.0V rail is not used by the GL8"5E motherboard.
Voltage Rail Tolerance
+5.0V DC ± 5%
+"2.0V DC ± 5%
-"2.0V DC ± "0%
+3.3V DC ± 4%
+5.0V DC standby ± 5%
It is very important that the power supply used can support the required load current on all
rails – failure to meet this can cause damage to the power supply or the motherboard. Pay
particular attention to the 5V Standby power requirement – the LAN controller (when fitted)
is powered from this rail.
The power supply must be properly approved by a third party agency for use in
IEC/EN/UL/CSA 1950/60950 applications.
3.8.3 General Purpose I/O Lines
Symbol Parameter Conditions Min Max Unit
V
IH
Input High Voltage 2.0 5.5 V
V
IL
Input Low Voltage -0.5 0.8 V
V
IN
= V
3.3V
"0µAI
IL
Input Leakage Current
V
IN
= V
GND
"0µA
V
H
Input Hysteresis 250 mV
V
OH
Output High Voltage I
OH
= -3mA 2.4 V
V
OL
Output Low Voltage I
OL
= 6mA 0.4 V
