Offline Flyback Transformer for Smart Meters Reduces Footprint by 30%

The MID-MHC series flyback transformers from Wurth Electronics Midcom, Inc. supports creepage and clearance distances up to 14mm, multiple isolated outputs, and power over 15W with 30% less footprint than the existing solution. This new series of flyback transformers has been specifically designed for use in smart metering applications.

“Many of our metering customers must meet strict safety standards with large creepage distance requirements,” said Chris Heisel, Product Manager for Metering and Telecom at Wurth Electronics Midcom. “Meanwhile, power requirements for data transmission are increasing, and power supply designers continue to struggle with noise at the transformer. The MID-MHC series employs creative new strategies to meet these challenges.”

The key is an innovative combination of core and bobbin design that employs a modified EP-core on a raised bobbin. The resulting package can support creepage and clearance requirements up to 14mm primary-to-secondary and up to 8mm between two secondary outputs. The raised design allows this to occur on a 22.1mm x 15.7mm footprint, which is 30-60% smaller than existing designs using horizontal E-core packages to achieve similar power levels.

Additionally, the EP-core design improves noise performance relative to E-core designs. The MID-MHC series includes universal input offline transformers with one to three outputs of 3.3 to 24V to demonstrate the capabilities of the package. Wurth Electronics Midcom will design custom transformers based on the MID-MHC package to meet individual customer’s applications.