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Diamond Point International

MEN Mikro PU3 - 3U 8 HP compactPCI Power Supply Unit PSU, 36 to 48 VDC, 35 W

H15 DIN 41612 plug, -40 to +85°C Screened

MEN Mikro PU3 - 3U cPCI 8 HP PSU, 36 to 48 VDC, 35 W
Key Features
19" rack mountable (VMEbus, CompactPCI®)
3U, 8 HP, conformal coating
Input 36-48 VDC nom. (25.2..60 V)
Max. input voltage range 21.6..67.2 V (EN 50155)
Output 3.3 V and 5 V, power 35 W
H15 DIN 41612 plug connector (front and rear)
-40 to +85°C screened
Complies with EN 50155 (railways)


MEN Mikro's PU3 is a 3U 8HP power supply unit is a plug-in device for 19" systems (e.g. VMEbus, CompactPCI®) and is especially designed for railway computer systems, being fully compliant with EN 50155.

The PU3 has a nominal input voltage of 36-48 VDC with a wide input range of 25.2..60 V and a max. input voltage range of 21.6..67.2 V (according to EN 50155). The otherwise identical PSU models PU2 and PU4 are available for the nominal input voltages of 24 VDC and 72-110 VDC respectively.

It is is controlled by a microprocessor which supervises the voltage and the temperature, as well as three external inputs and three outputs.

Thanks to the on-board intelligence the PSU can also act as an SMBus slave and communicate with the CPU board via the backplane. This allows the PSU to power on the system at a programmed date or it allows the CPU to make status polls with regard to error messages, time-out, on/off, for example.

The PSU provides a DC/DC converter to generate the isolated 5 V from the input voltage. A buck regulator generates 3.3 V from the 5 V isolated side. The maximum output power at full load is 35 W.

The subassembly is conformally coated, and components are secured against vibration. The PSU operates in -40 to +85°C environmental temperature. The thermal stress is extremely low due to integrated heat sinks and diversion of dissipated heat over the mounting surface.


Power Supply

InputNominal voltage input: 36-48 VDC
Wide input range: 0.7 x nominal voltage < nominal voltage < 1.25 x nominal voltage (according to EN50155): 25.2..60 VDC
Max. input voltage range: 0.6 x nominal voltage < nominal voltage < 1.4 x nominal voltage with full functionality for 0.1 s, no damage for 1 s (according to EN50155): 21.6..67.2 VDC
No load input power: 900 mW
Input and output via DIN 41612 plug connector, type H15
Output(s)Output power (max.): 35 W
5V tolerance: +5%/-3%
3.3V tolerance: ±3%
Overvoltage protection: +0.5 V/-0.2 V
Overtemperature shutdown: 50°...90°(adjustable by SMBus command)
Input and output via DIN 41612 plug connector, type H15
IsolationIsolation (according to EN 50155)
• Input/output: 1,500 VDC/1,000 Vrms
• Input/shield: 1,500 VDC/1,000 Vrms
• Output/shield: 1,500 VDC/1,000 Vrms
• Ground/shield: 1,500 VDC/1,000 Vrms
• Output voltage and temperature supervision (readable via SMBus)
• Overtemperature and overvoltage shutdown
• Communication with CPU
• Watchdog functionality
• Signals on back connector
• Voltage level 3.3 V
• Controlled by CPU
• Communication between the power supply unit and the CPU

3 binary inputs
• Max. voltage 154 VDC
• Electrically isolated
• External switch (key) with binary input
• Switch-on by key input or wake on time
• Switch-off by key input or software
• Status of binary inputs readable via SMBus
• User-specific functionality (depending on firmware)

3 binary outputs
• Max. voltage 154 VDC
• Isolated by relays
• User-specific functionality (controllable via SMBus)
• Maximum switching power: 60 W

DC/DC Converter
• Fuse-protected

Two status LEDs on front panel
• Green LED indicates correct input voltage
• Yellow LED indicates correct output voltage

Alternative power supply at the backplane for use as redundant PSU
Short circuit protection
Reverse polarity protection by internal protector
Fixed switching frequency: 250 KHz


ElectricalSee above
MechanicalDimensions: 3U, 8HP, 128.4 mm height
Integrated heat sink
Conformal CoatingAs standard
SoftwareDriver software for Windows®, Linux, VxWorks®
TemperatureTemperature range (operation): -40..+85°C
Temperature range (storage): -40..+85°C
Airflow: min. 10 m³/h

• Class of protection: Class II, EN 60950
• Degree of protection: IP20 (insert in rack), EN 60529
Weight665 g
VibrationVibration: according to EN 60068-2-6
ShockShock: according to EN 60068-2-27
Continuous shock: according to EN 60068-2-29
MTBF240,600 h @ 40°C (derived from MIL-HDBK-217F)
EMCTested according to EN 55022 (radio disturbance), EN 61000-4-2 (ESD), EN 61000-4-4 (burst) and EN 61000-4-5 (surge)
Warranty2 Years

Ordering Details

PU3 - 3U 8HP PSU, input 36 VDC nominal (25.2..45 V), output 5 V, 3.3 V, 35 W, H15 front/back, SMbus, external I/Os for key function, -40..+85°C screened, conformal coating
PU2 - 3U 8HP PSU, input 24 VDC nominal (16.8..30 V), output 5 V, 3.3 V, 35 W, H15 front/back, SMbus, external I/Os for key function, -40..+85°C screened, conformal coating

PU4 - 3U 8HP PSU, input 110 VDC nominal (77..137.5 V), output 5 V, 3.3 V, 35 W, H15 front/back, SMbus, external I/Os for key function, -40..+85°C screened, conformal coating