Question:
Will any ATX power supply work with my VersaLogic CPU board and VersaLogic power adapter
cable?
Background:
All VersaLogic CPU boards (with the exception of STD-type boards) require power from
an external power source. The most common source of power is an ATX power supply.
VersaLogic CPU boards are shipped with ATX power adapters.
Answer:
Yes and no! VersaLogic CPU boards and power adapters are designed to work with
standard ATX power supplies that comply with the connector pinout specified in the
ATX Specification (Version 2.1 or earlier; see "Specifications" below).
Warning! Dell Computer and possibly other consumer computer manufacturers use
proprietary pinouts on their power supplies and motherboards. These pinouts do not
adhere to ATX pinout standards even though their power supplies and motherboards
use an ATX style connector. Use of nonstandard ATX power supplies can cause
irreparable damage to VersaLogic CPU boards, which is not covered under our
warranty.
If you plan to incorporate a nonstandard ATX power supply into your application, you
must supply an adapter cable that provides the proper signals to the CPU board power
interface.
ATX Pinout:
The table below shows the standard ATX power connector pinout, along with the
pinouts of the power interfaces used on VersaLogic CPU boards. Consult the
VersaLogic reference manual for your CPU board for details.
Signal
Wire
1
Color
+3.3VDC
+3.3VDC
GND
+5VDC
GND
+5VDC
GND
PWR_OK
+5VSB
+12VDC
3.3 V
sense
Orange
Orange
Black
Red
Black
Red
Black
Gray
Purple
Yellow
Brown
Blue
ATX
Connector
(20 Pins)
10-Pin
Connector
2
(EPIC)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
5
—
2
7
3
8
—
—
6
4
—
9
—
1
—
10-Pin
Connector
3
(EPM)
7- and 3Pin
Connectors
4
(EBX)
7
—
1
2
3
8
5
—
—
4
—
6
—
—
—
5
—
2
1
3
7
6
—
—
4
—
AUX 3
—
—
—
12100 SW Tualatin Rd Tualatin Oregon 97062  (503) 747-2261  Info@VersaLogic.com  www.VersaLogic.com
-12VDC
GND
PS_ON#
GND
GND
GND
-5VDC
+5VDC
+5VDC
1.
2.
3.
4.
5.
Black
Green
Black
Black
Black
White5
Red
Red
16
17
18
19
20
—
10
—
—
—
—
9
—
10
—
—
AUX 2
AUX 1
—
—
VersaLogic recommends that you not rely solely on wire color to determine voltages. Before connecting a
power supply to a VersaLogic CPU board, measure the voltage of each pin with a voltmeter to prevent
possible damage.
Cable CBL/CBR-2022 used on EBX-12 (Cobra) and EPIC-2 (Gecko).
Cable CBL/CBR-1008 used on EPM-4 (Lynx), EPM-5 (Puma), EPM-CPU-3 (Bobcat), EPM-CPU-6/7
(Panther), EPM-CPU-10 (Jaguar).
Cable CBL-2021 used on VSBC-7 and VSBC-8, and CBL-2020 used on VSBC-6. These cables include a 7pin EBX-style connector and an auxiliary 3-pin connector for use with a PC/104-Plus (PCI) expansion
module.
ATX Specification Version 2.2 specifies this pin (pin 20 in the 24-pin connector configuration) as NC.
Specifications:
The following specifications contain more detailed information about standard power
connectors. Note that the ATX Specification listed here is Version 2.1. In ATX
Specification Version 2.2, the main power connector changed from 20 pins to 24 pins to
support PCI-Express requirements; however, some ATX Version 2.2 compliant power
supplies provide backward compatible connectors, or 20-pin to 24-pin ATX power
adapters can be used.



ATX Specification Version 2.1: 4.1 – Power Supply Connectors
EPIC Specification Version 1.0: Appendix A – Power Connector
EBX Specification Version 1.1: Chapter 5 – Power Connector and Power Requirements
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12100 SW Tualatin Rd Tualatin Oregon 97062  (503) 747-2261  Info@VersaLogic.com  www.VersaLogic.com