CUI Inc. – PES1-M and PEM1-S: DC/DC Converters Combine High Isolation and Wide Operating Temperature Range



CUI has introduced a family of low power board mounted DC/DC converters for use in harsh environments and demanding applications. 

The unregulated PEM series provides 3,000VDC of I/O isolation and a wide operating temperature range of -40°C to +105°C. There are two ranges of converters in the family: the PEM1-S devices are rated for a 1W output, and the PEM2-S for a 2W output.

CUI also produces the PES1-M, a surface mount DC/DC converter which provides an isolated 1W output.

The PEM and PES series incorporates a number of design and manufacturing improvements to previous generations of converters, providing for improved efficiency and thermal performance. Overall efficiency has been raised to as much as 89% at full load. The new design also enhances the devices’ performance across the load curve, reducing power consumption at light-load and no-load conditions, making these converters ideal for use in mobile and battery-powered devices.

The PEM converters are housed in a compact, industry standard 7-pin SIP package measuring 19.6 x 7 x 10mm, and the PES1-M in an 8-pin package measuring 12.7 x 8. x 7.25mm. Nominal inputs of 3.3V (except PES1-M), 5V, 12V, 15V and 24V (±10%) and output voltage configurations of 3.3V (except PES1-M), 5V, 9V, 12V, 15V, 24V, ±5V, ±12V, ±15V, and ±24V are available.

To provide an additional layer of protection for sensitive loads, the converters also come with continuous short circuit protection and 8kV of ESD protection.


  • Medical equipment
  • Industrial control equipment
  • Mixed signal systems
  • Security equipment

  • Typical efficiency (PEM1-S/PEM2-S/PES1-M): 79% to 81%/84% to 89%/80% to 81%
  • 300kHz maximum switching frequency at full load
  • 1,000MΩ isolation resistance at 500V
  • 3,500,000 hours mean time before failure