SMD Transformer Provides 3,750 Volt RMS Isolation for Embedded Circuits, Battery Monitors

ESMIT-4180C provides isolation in battery monitorsThe Sumida ESMIT-4180/C series Isolation Transformer is the latest entry into Sumida’s line of low-profile, surface mounted isolation transformers.  It was developed to better respond to the demands of the embedded-circuit based products, including automotive battery monitoring, high-speed modems and other circuits.  As an example, the ESMIT-4180/C is included in the reference design for the NXP Freescale MC33771 and MC33664 High Voltage Battery Cell Controller and Transformer Physical Layer.  This comprises a high-voltage battery management system.

The Sumida ESMIT-4180/C offers AEC-Q200 certification and a very high, 3,750 volt RMS, one second isolation capability (equivalent to a full minute at 3,000 volts RMS).  Other specifications are consistent with the signal and high voltage isolation needs of digital data devices.

The need for a compact device to safely isolate signals from a power source is not limited to automotive circuits.  Other applications are found in telecommunications and industrial products.  For example, in telecom, the ESMIT-4180/C is used in the Conexant CX86600 Modem Reference Design; and has application in other serial/parallel modem circuits.  Similar signal isolation needs are a fit for potential applications in factory environments for IIoT, data logging and control systems.

Because of Sumida’s extensive experience in inductive products and core material compositions, it was possible to meet performance objectives while keeping package size to a minimum.  With a footprint of only 5.2 by 7.1 mm, the device is well sized for the tightest PC boards. Completing the design, this toroidal transformer is entirely encapsulated, providing added mechanical protection.

The nominal inductance value is 120µH, as measured at 100kHz.  DCR is 0.25W.  The device is RoHS compliant and halogen-free.  The ESMIT-4180/C  series offers a full-rated temperature range of -40° to +125°C, and solder reflow temperature to 260°C peak.