M2-ATX
6-24V Intelligent Automotive ATX Power Supply
Installation Guide
Version 1.4 (firmware v1.5, 10/15/2009)
P/N M2-ATX-01
Before you start…
Please take a moment and read this manual before you install the M2-ATX in
your
vehicle. Often times, rushing into installing the unit can result in serious damage
to your M2-ATX board, computer and probably your car’s electrical system.
The M2-ATX board has several wires that need to be installed in various
places.
When installing, always double check the polarity of your wires with a
voltmeter.
Avoid using the cigarette plug as a power source, often times the contacts are
not capable of delivering high current to your PC.
1.0 Introduction
Thank you for purchasing the M2-ATX power sequencer / vehicle ATX power
supply.
The M2-ATX was designed to work with a wide variety of main boards such as
the VIA mini-ITX motherboards as well as Pentium-M, Celeron or certain full
power Core Duo systems.
1.1 M2-ATX Logic Diagram
+
Battery
GND
PC
+
Reverse and
forward protection
Switch Logic
6-30V DC-DC
ATX PSU
ATX power
-
Ignition
SW
8bit MCU
Amplifier
Enable
J6
M2-ATX
J8
MotherBoard
ON/OFF switch
J9
Optional On/OFF switch
J5
LED
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1.2 M2-ATX Connection diagram
M2-ATX, top view
Power Input Connectors
J1
Battery + (un-switched battery, positive)
J3
Ignition (To start connect to Battery +). Do not use in the standard
PSU mode (mode P0)
J4
Battery - (negative)
Controls and Settings
J6
Controls amplifier via remote ON/OFF. Left pin is RMT, Right pin is
GND
J8
To motherboard ON/OFF switch
J10
User jumper settings (A,B,C,D)
J9
To external ON/OFF switch (optional, J8 is in parallel with J9)
Power Output Connectors
J2
Optional P4-12V power
J7
ATX power connector (to motherboard)
J5
To LED (optional)
Jumper attached=ON
A
B
C
D
P
Off-delay
(All rails ON)
Hard-off
(5VSB)
OFF OFF
OFF OFF
P0
ON
OFF OFF
P1
5s + 1min AutoLatch*
1 min
OFF OFF
P2
5s+ 1min AutoLatch*
2 hour
OFF
OFF ON
ON
ON
Standard PSU mode
OFF OFF
P3
5s+ 1min AutoLatch*
NEVER
OFF OFF
ON
OFF
P4
30s + 1min AutoLatch*
2 hour
ON
ON
OFF
P5
30s + 1min AutoLatch*
NEVER
ON
OFF
P6
30min
NEVER
ON
OFF
OFF
OFF ON
ON
ON
P7
3 hour
NEVER
OFF OFF
OFF ON
P8
10 min
1 hour
ON
OFF ON
P9
15 min
2 hours
OFF ON
P10
1 hour
75min
OFF
OFF ON
IMPORTANT:
Always use the
“Hibernate” feature,
never use “Standby”
as it can severely
discharge your
battery over
extended periods of
time.
NEVER use “Hardoff = NEVER”
settings unless you
understand the risks
of battery depletion.
“Hard-off=NEVER
always keeps 5VSB
rail ON!
*AutoLatch is active during the fist 60s of PC operation (and only during the
first 60 seconds). For example, If Ignition is turned ON and then OFF right
away, M2-ATX will latch Ignition in ON position for the next 60 seconds,
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allowing your operating system to fully come up. This will prevent disk drive
corruption or systems that remain hung in the ON position. After the first 60
seconds of system operation, the AutoLatch feature will be removed and
system will shut down at as governed by the “Off-delay” setting.
P0: In this mode, the M2-ATX behaves like a regular ATX power supply. If J6 is
connected to the motherboard, M2-ATX will also send a gratuitous “ON pulse”
to the motherboard right after power is first applied. If IGNITION is connected
to the battery, the unit will shut down if battery is < 11.2V. This is to protect
the battery from over-discharging. If Ignition is not hooked up, M2-ATX will
operate from as low as 6V. For more information, please consult the “UPS
mode” documentation on the product page.
P1 (recommended): Sends ON pulse to motherboard when ignition is ON for
more than 5 seconds, sends OFF pulse to motherboard 5 seconds after
ignition is turned off. Waits another 60 seconds and then shuts down 5VSB to
conserve battery. In this mode, the M2-ATX consumes less than 0.5mA. This
is our recommended setting.
1.2 Power challenges in a Vehicle PC
The 5V Standby Problem: One of most difficult tasks of operating a PC in a
vehicle is power consumption while the computer is OFF. Even when your
computer is OFF or in Suspend, it will still consume about 50-150mA on the
5VSB rail. No matter how big your battery is, you will eventually drain it if proper
actions are not taken.
The M2-ATX is addressing these issues by cutting off the 5VSB rail after a predefined amount of time (see jumper chart, HARDOFF). When 5VSB is always
active (HARDOFF=Never), M2-ATX constantly monitors the battery levels.
When battery level drops below 11V for more than one minute, M2-ATX will
shut down and re-activate only when the input voltage is > 12V.
Engine Cranks, under-voltage and over-voltage situations. Another difficult
task is maintaining stable 3.3V, 5V, 12V and -12V power to your PC. While car
batteries are rated at 12V, they actually provide voltages in between 7-16V
(engine cranks) or as high as 80 volts (load dump). Most of the times, your
battery will stay at 13.5V (while car is running) but extra precautions need to
take place in order to prevent such situations. M2-ATX can operate as low as
6V and as high as 28V while providing strict regulation on all rails along with
input voltage clamping and reverse protection.
Loud amplifier pops when PC starts. If your PC is connected to your car
amplifier, you will hear a loud pop when the computer is first started. The M2ATX has an ‘anti-thump’ control that will keep your amp OFF while the PC
starts. Simply connect J6 to your amplifier remote control pins to activate the
‘anti-thump’ feature.
2.0 Mode of operation
1)
Ignition=OFF. Nothing happens. M2-ATX is waiting for ignition signals.
2)
Ignition=ON. M2-ATX waits for few seconds then turns on the 5VSB rail. After another
second M2-ATX sends an “ON” signal to the motherboard via the 2 wires connected to the
motherboard’s ON/OFF pins. The motherboard will turn ON and your system should start
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booting. The Ignition state will be latched for 60 more seconds so that the motherboard will
have a change to come up in a clean manner.
3)
Ignition=ON. Your computer will remain ON.
4)
Ignition=OFF. M2-ATX waits for “OFFDELAY” in seconds (see jumper chart) and then it turns
the motherboard OFF by sending a signal to the motherboard’s ON/OFF switch. Your
computer should turn off gracefully (shutdown procedure). After shutdown, 5VSB will still be
provided for another “HARDOFF” seconds. In the event where the shutdown process is
longer than “HARDOFF” (Operating System gets frozen, etc), power will be shut down hard,
turning off all power rails. During the HARDOFF procedure, the battery levels will be
constantly monitored to prevent deep discharge situations.
5)
M2-ATX will go to step 1, if ignition is tuned ON again.
3.0 M2-ATX Characteristics
Minimum Input Operating. voltage
Maximum input Operating voltage
Deep-Discharge shutdown
threshold
Input current limit (fuse protected)
Max Output Power
Operating temperature
Storage temperature
MTBF
Efficiency (Input 9-16V)
PCB size
Input connectors
Output Connector
6V
24V (clamping will occur at 25-27V)
11.2V
15A (15A mini-blade fuse)
160 Watts
-40 to +85* degrees Celsius
-55 to +125 degrees Celsius
192,000 hrs @ 50C, 96,000 hrs @65C
>94%, all rails combined, 50% load.
160x45mm
Faston 0.25” terminal
ATX Power 20 pin (Molex P/N 39-01-2200
*Units starts failing at ~115 Celsius. Operating at temperatures above 85C / 185F will drastically reduce the MTBF. When
operating at high temperatures or fanless operation, must reduce PSU load by 25%.
99
12V rail Efficiency (%)
96
93
90
87
84
Iout = 5A
81
Iout = 6A
78
Iout = 8A
75
6
8
10
12
14
16
18
Vin (V)
Maximum Power Characteristics
Output Rail
Current (Max)
Current Peak
(<60 seconds)
5V
8A
10A
3.3V
8A
10A
5VSB
1.5A
2A
-12V
0.15A
0.2A
12V
8A* (see below) 10A
Regulation
1.5%
1.5%
1.5%
5-%
2%
Total power = 169.9 Watts
When operating at 24V or extreme temperatures, de-rate by 30-50%, ventilation will be required.
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12V Rail Output Current
Input (V)
12V rail current Input (V)
12V rail current
6V
4A
11V
8A
7V
5A
12V
8A
8V
6A
14V
8.5A
9V
7A
14-18V
9A
10V
8A
20-26V
7A
For low input voltage (6-10V) ventilation might be required for peak load
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