KTQ87/mITX Users Guide
KTD-N0882-D Page 31
6 Internal Connectors
6.1 Power Connector (ATX/BTXPWR)
The KTQ87 boards are designed to be supplied from a standard ATX (or BTX) power supply. Use of
BTX supply is not required for operation, but may be required to drive high-power PCIe cards.
ATX/ BTX Power Connector (PWR1):
Note
Type Signal
PIN Signal Type
Note
PWR
3V3
12 24
GND
PWR
PWR
+12V
11 23
5V
PWR
PWR
+12V
10 22
5V
PWR
PWR
SB5V
9
21
5V
PWR
I
P_OK
8
20
-5V
PWR
1
PWR
GND
7
19
GND
PWR
PWR
5V
6
18
GND
PWR
PWR
GND
5
17
GND
PWR
PWR
5V
4
16
PSON#
OC
PWR
GND
3
15
GND
PWR
PWR
3V3
2
14
-12V
PWR
PWR
3V3
1
13
3V3
PWR
Note 1
: -5V supply is not used on-board.
See chapter “Power Consumption” regarding input tolerances on 3.3V, 5V, SB5V, +12 and -12V (also
refer to ATX specification version 2.2).
ATX+12V-4pin Power Connector (ATXP1):
Note
Type Signal
PIN
Signal Type
Note
PWR
GND
2
4
+12V
PWR
1
PWR
GND
1
3
+12V
PWR
1
Note 1
: Use of the 4-pin ATX+12V Power Connector is required for operation of KTQ87.
Warning
: Hot Plugging power supply is not supported. Hot plugging might damage the board.
Signal
Description
P_OK
P_OK is a power good signal and should be asserted high by the power supply to indicate
that the +5VDC and +3.3VDC outputs are above the under-voltage thresholds of the power
supply. When this signal is asserted high, there should be sufficient energy stored by the
converter to guarantee continuous power operation within specification. Conversely, when
the output voltages fall below the under-voltage threshold, or when mains power has been
removed for a time sufficiently long so that power supply operation is no longer guaranteed,
P_OK should be de-asserted to a low state. The recommended electrical and timing
characteristics of the P_OK (PWR_OK) signal are provided in the
ATX12V Power
SupplyDesign Guide
.
It is strongly recommended to use an ATX or BTX supply, in order to implement the
supervision of the 5V and 3V3 supplies. These supplies are not supervised on-board.
PS_ON# Active low open drain signal from the board to the power supply to turn on the power supply
outputs. Signal must be pulled high by the power supply.
Internal Connectors