PU3 - Power Supply Unit, 36 to 48 VDC, 35 W (Product Discontinued)

The PU3 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 allowsthe 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.

Features

  • 19" rack mountable
  • 3U, 8 HP
  • Input 36 to 48 VDC nom. (25.2..60 V)
  • Max. input voltage range 21.6 to 67.2 V (according to EN 50155)
  • Output 3.3 V and 5 V
  • Power 35 W
  • H15 DIN 41612 plug connector (front and rear)
  • SMBus
  • External I/Os for key function
  • -40 °C to +85 °C
  • Conformal coating
  • Complies with EN 50155 (railways)

Specifications

Microcontroller
  • Output voltage and temperature supervision (readable via SMBus)
  • Overtemperature and overvoltage shutdown
  • Communication with CPU
  • Watchdog functionality
SMBus
  • Signals on back connector
  • Voltage level 3.3 V
  • Controlled by CPU
  • Communication between the power supply unit and the CPU
Binary I/O
  • 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
Miscellaneous
  • 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
Input Characteristics
  • Nominal voltage input: 36-48 VDC
  • Wide input range: 0.7 x nominal voltage < nominal voltage < 1.25 x nominal voltage (according to EN 50155)
    • 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 EN 50155)
    • 21.6..67.2 VDC
  • No load input power: 900 mW
Output Characteristics
  • 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)
Connection
Input and output via DIN 41612 plug connector, type H15
Electrical Specifications
  • Isolation (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
  • MTBF: 240,600 h @ 40°C (derived from MIL-HDBK-217F)
Mechanical Specifications
  • Dimensions: 3U, 8HP, 128.4 mm height
  • Integrated heat sink
  • Weight: 665 g
Environmental Specifications
  • Temperature range (operation): -40..+85°C
  • Temperature range (storage): -40..+85°C
  • Airflow: min. 10 m³/h
  • Shock: according to EN 60068-2-27
  • Continuous shock: according to EN 60068-2-29
  • Vibration: according to EN 60068-2-6
  • Protection
    • Class of protection: Class II, EN 60950
    • Degree of protection: IP20 (insert in rack), EN 60529
EMC
Tested according to EN 55022 (radio disturbance), EN 61000-4-2 (ESD), EN 61000-4-4 (burst) and EN 61000-4-5 (surge)
Software Support

Downloads