Evaluation Board Manual
Preliminary
PPC750FX Evaluation Board
750FXebm_ch10.fm
June 10, 2003
Connectors
Page 55 of 115
10.1 Auxiliary Power
The board is equipped with a standard ATX power connector. This allows the board to be externally powered
from a standard ATX power supply when it is not installed in a PCI slot.
Note: If the board is plugged into a PCI slot, the external ATX power supply will not activate under any
conditions, and pressing the ATX power-on pushbutton (U53) will have no effect.
Figure 10-2. ATX Power Supply Connector—J34
Table 10-2. ATX Power Signals—J34
Pin
Name
Comment
1
+3.3V
Tolerance ± 4%
2
+3.3V
Tolerance ± 4%
3
GND
4
+5V
Tolerance ± 5%
5
GND
6
+5V
Tolerance ± 5%
7
GND
8
Power OK
Active high indicator that +5V and +3.3V are above their undervoltage thresholds
9
+5V SB
Standby power, at least 10 mA, tolerance ± 5%
10
+12V
Not used
11
+3.3V
Tolerance ± 4%. Remote 3.3V sense.
12
-12V
Not used
13
GND
14
PS-ON
Active low signal that turns on the ATX power supply.
15
GND
16
GND
17
GND
18
-5V
Not used
19
+5V
Tolerance ± 5%
20
+5V
Tolerance ± 5%
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
