M4-ATX
6-30V Intelligent ATX Power Supply
Installation Guide
Version 1.0e
P/N M4-ATX-01
Before you start…
Please take a moment and read this manual before you install the M4-ATX in your vehicle. Often times, rushing into installing the unit can result in serious damage to your M4-ATX board, computer and probably your car’s electrical system. 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.
Introduction
Thank you for purchasing the M4-ATX power sequencer / vehicle ATX power supply.
The M4-ATX was designed to work with a wide variety of main boards ranging from low power to fully fledged Intel, AMD or VIA motherboards.
M4-ATX Logic Diagram
Battery
Ignition SW
Amplifie r
Enable
+
GND
+
-
Reverse and forward protection
Switch Logic
8bit MCU
M4-ATX
6-30V DC-DC
ATX PSU
PC
ATX power
Mother Board
ON/OFF switch
Status LED
USB
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1.2 M4-ATX Connection diagram
Power Input Connectors (bottom, right)
Left
Center
Battery negative (GND)
Ignition ( To start connect to Battery +). Do not use in the standard PSU mode
(mode P0)
Right Battery positive (+)
(A) ATX Power Output Connector 20/24 pin connector
(B) 12V-ATX power output connector 4 pin
(C) Configuration dip switches
(J5) For internal use only (do not use)
(J6) Amplifier THUMP wire harness (connects to the M4-ATX pin header)
(J3) Fan Header. Positive pin is closest to “J3” marking.
(J8) USB, Motherboard ON/OFF and THUMP (Thump also available on J6)
1) GND
2) GND
3) USB D+
4) USB D-
5) Vcc
6) To Motherboard ON/OFF
7) To motherboard ON/OFF
8) Amplifier Thump
9) GND
19 N/C (key)
J8 shown with cable harness connected to the motherboard ON-OFF header (pin 7 and 6)
M4-ATX User Guide Page 2
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DIP Switch (ON=down)
1 2 3
OFF OFF OFF
ON OFF OFF
OFF ON OFF
ON ON OFF
OFF OFF ON
ON OFF ON
OFF ON ON
ON ON ON
P
Off-delay
(All rails ON)
Hard-off
(5VSB)
P0 Standard PSU mode
P1 5sec + 1min AutoLatch* 1 min
P2 1min + 1min AutoLatch* NEVER
P3 1min + 1min AutoLatch* 1min
P4 15min 1min
P5 15min
P6 30min
P7 2hour
NEVER
1min
NEVER
IMP ORTANT: Always use the
“Hibernate” feature, never use
“Standby” as it can severely discharge your battery over extended periods of time.
NEVER use “hard-off = NEVER” settings unless you understand the risks of battery depletion. Even with safety limits in place, your battery might be not be able to start your engine. “Hard-off=NEVER keeps your 5VSB rail on at all times”
*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, M4-ATX will latch Ignition in ON position for the next 60 seconds, 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 M4-ATX behaves like a regular ATX power supply. If J6 is connected to the motherboard, M4-ATX will also send a gratuitous “ON pulse” to the motherboard right after power is first applied.
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
M4-ATX consumes less than 0.5mA. This is our recommended setting.
NOTE: Should you need to reset to factory defaults (in case changes were made via the USB uplink), simply power off the unit, connect a jumper to JP1 and then apply power back up for more than 2 seconds. The LED light will start to flash rapidly indicating that the factory defaults were loaded. Don’t forget to Remove jumper! Disconnect M4-ATX from battery for at least few seconds. You are done!
Power challenges in a vehicle PC: 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 M4-ATX is addressing these issues by cutting off the 5VSB rail after a pre-defined amount of time (see jumper chart, HARDOFF). During HARDOFF if the battery level drops below 11.2V for more than one minute, M4-ATX will shut down and re-activate only when the input voltage is above 12V.
Engine Cranks, under-voltage and over-voltage situations. Another difficult task is maintaining stable power to your PC. While car batteries are rated at 12V, they actually provide voltages in between 8-16V (engine cranks) or as high as 80 volts (load dump).
Most times, your battery will stay at 13.5V but extra precautions need to take place in
M4-ATX User Guide Page 3
www.mini-itx.com/store/psu order to prevent such situations. M4-ATX operates as low as 6V and as high as 30V while providing strict regulation as well as input voltage clamping and reverse protection.
Anti-Thump: If your PC is connected to your car amplifier, you will hear a loud pop when the computer is first started. The M4-ATX has an ‘anti-thump’ control that will keep your amp OFF while the PC starts. Simply connect the 2 pin wire to J6 harness to your amplifier remote control pins. The pin at the edge of the PCB is GND, inner pin is HOT.
Mode of operation explained
1) Ignition=OFF. Nothing happens. M4-ATX is waiting for ignition signals.
2) Ignition=ON. M4-ATX waits for few seconds then turns on the 5VSB rail. After another second M4-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 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)
4)
5)
Ignition=ON. Your computer will remain ON.
Ignition=OFF. M4-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.
M4-ATX will go to step 1, if ignition is tuned ON again.
NOTE. When all dip switches are off, M4-ATX acts as a regular power supply. M4-ATX will also send a gratuitous “ON” pulse (to the ON/OFF motherboard pins, should you have a wire harness connected to it) when power is applied for the first time. Do not connect the on/off switch if you don’t want your PC to be started automatically.
M4-ATX Characteristics
Minimum Input Operating. voltage
Maximum input Operating voltage
Deep-Discharge shutdown threshold
Input current limit (fuse protected)
Max Output Power
Deep Sleep Current Consumption.
Storage and operating temperature
MTBF
Efficiency (Input 10-16V)
6V
30V (hard clamping will occur at 34V)
11.2V
Mini-blade 25A
250 Watts / 300 watts peak
< 1.6mA
-40 to +125 degrees Celsius (storage), -40 – 65C (operating)
200,000 Hrs
>95%, all rails combined, 50% load.
Input connectors
Output Connector
M4 screw terminal
ATX Power 24 pin (Molex P/N 39-01-2200)
*Unit shuts down when internal temperature sensor indicates > 85C. This value can be changed with software.
Maximum Power Characteristics
Output Rail
5V
3.3V
5VSB
-12V
12V
Current (Max)
15A
15A
1.5A
0.15A
12A (see below)
Current Peak
(<30 seconds)
20A
20A
2A
0.2A
16A (see below)
Regulation
1.5%
1.5%
1.5%
10%
2%
When operating at <8V or >28V or extreme temperatures, de-rate by 25-50%, ventilation might be required.
When operating at constant 160watts or more forced ventilation might be required.
12V Rail Output Current (12V buck/boost converter)
Input (V) 12V out current Input (V)
6-8V
8-11V
8A
10A (12A peak)
11-16V
16-30V
12V out current
12A (16A peak)
12A (14A peak)
M4-ATX User Guide Page 4