The PA4040 series of chokes integrate a common mode (CM) and differential mode (DM) choke into the same component.

Why combine the two? Combining two separate magnetic components into a single integrated component reduces power losses across the EMI filter portion of the power supply because it reduces the resistance. It also allows for a reduction in the overall space needed for the choke. Geoffrey Wildman, Global Marketing Manager for Pulse Electronics Power BU explained:

“Integrated chokes have been available before, but mainly for custom applications. This catalog release allows for a wider range of customers to enjoy the benefits of integrating the CM and DM chokes.”

PA4040 Key Features

Our new PA4040 integrated choke is considered part of our family of Common Mode Chokes. It has a small 31×24.9mm footprint, making this single CMDM component over 40% smaller than the combined footprint of equivalent CM and DM components. The low direct current resistance, between 32 and 245 mOhms, increases efficiency by 30%. Placing one component, instead of two, saves manufacturing time, costs, and increases throughput.

  • Common Mode and Differential Mode Choke intergrated into a single component reducing overall losses and reducing footprint
  • Dielectric Strength: 1500Vrms
  • Common Mode Inductance: 4.5mH (1Arms) to 0.28mH (3.5Arms)
  • Differential Mode Inductance: 685uH (1.33Apk) to 55uH (4.6Apk)
  • Size (LxWxH): 31.0mm x 24.9mm x 16.5 mm Max
  • Safety Spacing: 3.0mm creepage and clearance between windings, 1.5mm between windings and core

PA4040 Applications

The PA4040 integrated choke has 1500Vrms hi-pot and 3.0mm of creepage and clearance safety distance so it suits a wide range of safety agency (UL/CSA/VDE) requirements. It can be used in any AC/DC or DC/AC power supply that uses both a DM and CM filter and where the currents through the filter are less than 3.5Arms. Applications include…

  • LED lighting drives
  • Solar micro-inverters
  • Motor drives and controls
  • Datacom
  • Computing.

It’s an extremely cost efficient option as the cost is approximately 20% lower than that of two separate CM and DM components. Regarding application of this new series, John Gallagher, Field Applications Engineer for Pulse Electronics Power BU said:

“For power supply EMI filter designers looking to increase power density, improve efficiency, and reduce overall cost, the PA4040 series of integrated common mode and differential mode chokes is an exciting development.”

PA4040 Mechanical & Schematic


More About Common Mode & Differential Mode Chokes

Common Mode Chokes are used to block or divert unwanted common mode noise in a power supply. Common mode is noise that is common to both the line and neutral in a power supply and essentially circulates through line/neutral and then returns through earth ground by way of parasitic elements in the power supply.

Differential Mode Chokes block or divert unwanted differential mode noise in a power supply. Differential mode is noise that circulates through the line and returns through the neutral.

Our new PA4040 component combines these two functions into a single integrated CMDM choke.

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