New Industry Products

Absopulse Debuts New Line of Encapsulated 250W DC-DC Converters

September 08, 2021 by Gary Elinoff

The convection cooled units provide 12, 24, 36, 48, or 72VDC and operate from inputs centered on 24, 48, or 125VDC

The PDC 250-HSA series is aimed at heavy-duty industrial applications. The latest addition to the company’s line of fully encapsulated, convection cooled DC/DC converters, the industrial quality units are cooled by convection cooling made through its heatsink assembly block. This is achieved with no need for either contact with a heat sinking surface or for forced airflow.

The PDC 250-HSA-P59 series. Image courtesy of Absopulse


Members of the Series

These converters deliver a single output of either 12VDC, 24VDC, 36VDC, 48VDC, or 72VDC. They operate from either 24VDC (21V-30V), 48VDC (42V-60V), or 125VDC (95V-140V). The output floats, so either plus or minus can be ground. Absopulse points out that customized output and input values are also available.

Output regulation is 1% or better from zero to full load, and across all specified line variation. At full load, converter efficiency is specced at 80%.


The Benefits of Encapsulation

Encapsulation of the converters protects internal components from ambient dirt, dust, pollutants, and moisture. It also assures that any heat generated in the apparatus is dissipated throughout the entire module.

Potting involves filling the unit’s interior with a MIL-grade silicon rubber compound with a UL94V-0 flammability rating. This serves to provide immunity to shock, vibration, and humidity. Because the compound employed is also thermally conductive, it also serves to improve the process of even heat distribution.


The Heatsink

The heatsink assembly block, HSA-P59, was designed specifically for the encapsulated module, and is shown under the module in the earlier illustration. It can be mounted either on a chassis or on a DIN-rail, with the mounting clips that are provided. Additionally, it can be mounted even on thermally non-conductive surfaces, such as plastic, wood, or bricks. Absopulse provides a complete dimensional analysis of the heatsink assembly block.



Isolation protections include:

  • 1000VDC input to chassis
  • 1500VDC input to output
  • 500VDC output to chassis

Inrush current limiting

Short-circuit protection on the output

In the event of insufficient cooling, there is thermal shutdown with automatic reset


Important Specifications

  • The unit switches at 55kHz ±3kHz
  • Redundancy diode is an option
  • Output ripple and noise are less than 1% of peak to peak output voltage, or 0.2% Vrms, over a 20MHz bandwidth
  • Temperature drift 0.03% per ℃ over the device’s entire operating temperature range.



Members of the PDC 250-HSA-P59 series are suited for operation in extreme environments such as:

  • Transportation
  • Heavy industry
  • Mining
  • Oil rigs
  • Military applications
  • Power generation
  • Power distribution



  • Series members are specified for operation over a -40 to +70oC cold plate temperature range with no derating. Absopulse states that wider operating temperature ranges may also be possible
  • Dimensions are 5 x 3.8 x 9.1 inches
  • Weight is 5.9 lbs


Regulatory and Safety

  • Complies with the EN55032 standard for EMC Class A by a wide margins, with Class B compliance available as an option.
  • Meets EN/UL60950-1 and with equivalent UL and CSA equivalents
  • Shock/Vibration as per IEC 61373 Cat 1 A and B



  • RoHS compliant