3W dc-dc converters with 3kV isolation, 4:1 input range and 2MoOP

Author: EIS Release Date: Sep 8, 2020


Cosel has announced a series of high isolation 3W dc-dc converters for medical and industrial applications.

Cosel-MH3-dcdc

Isolation in the MH3 series is 3kVac and 4.2kVdc, and for medical applications the parts offer two means of operator protection (2x MoOP, 250Vac) isolation to IEC60601-1 3rd edition.

There is a choice of input ranges, each spanning a 4:1 ratio:

  • 4.5V – 18V
  • 9V – 36V
  • 18V – 76V

There there is also a choice of single (MHFS3) and dual (MHFW3) output:

  • 3.3V
  • 5V
  • 9V
  • 12V
  • +/-12V
  • +/-15V

Dual outputs can be used in series to deliver 24V or 30V.

Single output parts have trimmable (from the secondary side) output voltages.

As well as medical applications, industrial use is foreseen.

“The series has a reinforced insulation and its transformer is designed to sustain differential voltage that might happen in industrial applications,” according to the company. “With expertise in designing power supplies for equipment using IGBT drivers, Cosel applied high-power isolation best practice to the low power MH3 series to reduce isolation fatigue resulting from differential high voltage happening in motor control or IGBT drivers.” Adding that life expectancy curves are provide in the assocaited applications manual.

Packaging is 22 x 12 x 9.5mm (7gram) 8pin single-in-line. Against shock and vibration, the connection/mounting pins are moulded into an epoxy holder. Vibration testing is to 10g (10 – 55Hz, X, Y and Z axis) and shock testing is 50g (once on each axis).

Operation is over -40 to +85°C ambient and 20 – 95% relative humidity (non condensing). Depending on cooling, and with derating, operation can be up to +105°C at the specified measuring point.

Against noise transfer, capacitance over the isolation barrier is 20pF max “which is a great benefit when powering motor control systems”, according to the company.

Over-current protection is built-in and a remote on-off pin is standard (low = on).

Approvals include: UL62368-1, EN62368-1, c-UL (equivalent to CAN/CSA-C22.2 No.62368-1), ANSI/AAMI ES60601-1, EN60601-1 3rd, c-UL (equivalent to CAN/CSA-C22.2 No.60601-1).

RoHS directive is complied with and the series is CE marked in accordance with the Low Voltage Directive.

Manufacturing is in Japan, and the warranty is five years.