Mini-ITX Power Solutions Andrei Bulucea
Automotive Solutions Ituner Networks
DC-DC converters - 7 - Automotive Applications
Power Rails Description
All ATX power supplies have several power outputs. Please see below a matrix indicating the
uses for each power rail along with comments related to the power consumption.
Rail Circuit Type Board Type Comments
+12 V
3.5", 5.25 motors, fans, P4
power
Mostly P4 boards (lots of
power), FET drive on all
boards (little power).
Use PW-60a or PW-70a only when using
3.5" drives or P4s.
+ 5 V
General M/B and disk
circuitry, memory, laptop
drive motors.
ll Boards
ll our DC-DC converters have adequate
power on this rail
+ 3.3 V CPU core, memory
EPIA-5000, 800, V, M-
1000, M-2, CL, etc
PW-60/PW70 DC-DC converters have
adequate power on this rail in all cases.
-12 V
Some (older) serial ports
chipsets
EPIA-M, EPIA-M2 (EPIA-
5000/800/V does not use
the –12 V for serial ports)
Check the serial driver chipset. Modern
serial chipsets do not use the –12 V rail.
- 5 V Obsolete NONE No longer needed on any boards.
+5 V SB
Memory, vital sleep
functions.
LL Uses little power.
Power Consumption Charts
The EPIA boards consume different amounts of power in different situations. When idle, the
boards consume little power, when in use by highly demanding applications they tend to consume
more. Please see below the power consumption charts for various mini-ITX boards.
Hint: It seems that the mini-ITX boards consume the most power when the computer is in the
BIOS administration pages. Do not ask why this happens, it is a fact! If you want to check the
thermal design of your enclosure without having to run intensive applications, just put your PC in
the BIOS mode.
To measure the total power consumption of your system, connect a digital Amp Meter in series
with the 12 V in of your DC-DC power converter. (Do not try to measure the current consumption
of your AC power supply as this operates at high voltages). Multiply the reading from your Amp
Meter and multiply it by 12 to get the total power consumption. For example, if your EPIA-5000
current consumption is 0.7 A, then the total power consumption is 8.4 W.
EPIA 5000 Power Consumption
Playing DVD
Nominal Voltage Actual Voltage, V
A
Actual Current, I
Power, P = V
A
x I
+3.3 V 3.37 V 2.43 A 8.19 W
+5 V 4.97 V 1.21 A 6.01 W
5 V SB 5.04 V 0.038 A 0.19 W
+12 V 12.28 V 0.064 A 0.79 W
Total Power: 15.18 W
Playing MP3
Nominal Voltage Actual Voltage, V
A
Actual Current, I
Power, P = V
A
x I
+3.3 V 3.37 V 2.01 A 6.77 W
+5 V 4.97 V 1.15 A 5.72 W
5 V SB 5.04 V 0.038 A 0.19 W
+12 V 12.28 V 0.065 A 0.80 W
Total Power: 13.18 W
Running Network Applications
(55 paginas)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comentarios a estos manuales