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OverviewAll product unitsProduct unitPassive ComponentsProduct groupSignal & CommunicationsProduct familySignal TransformerProduct seriesWE-BMS Transformer for Battery Management Systems
OverviewAll product unitsProduct unitPassive ComponentsProduct groupSignal & CommunicationsProduct familySignal TransformerProduct seriesWE-BMS Transformer for Battery Management Systems

WE-BMS Transformer for Battery Management Systems

LTSpice files

Characteristics

  • Galvanic Isolation of 4300 VDC / 1 min.
  • Up to 1000 VDC working voltage
  • Integrated filter chokes for common mode suppression
  • Supports serial daisy chain isoSPI and SPI
  • AEC-Q200 qualification
  • Available in different footprints
  • Low profile versions
  • Operating temperature: -40°C up to +125°C

Applications

  • Energy Storage systems
  • Uninterrupted Power Supply (UPS)
  • E-bikes, E-scooters

Products

Order Code Data­sheet DownloadsPortsVT DC
(V (DC))		Working Voltage
(V (DC))		Cr
(mm)		L
(mm)		W
(mm)		H
(mm)		 Samples
74941300SPEC
8 files

EDA models: Components
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 1 4300 1000 6 7.6 9.5 5.5
74941301SPEC
8 files

EDA models: Components
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CAD files
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Electric models
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 1 4300 1000 5 7.6 9.5 5.5
74941302SPEC
8 files

EDA models: Components
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CAD files
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Electric models
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 1 4300 1000 10 9.5 15.4 3.45
74942300SPEC
8 files

EDA models: Components
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CAD files
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Electric models
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 2 4300 1000 10 15.1 14.7 4.75
74942301SPEC
8 files

EDA models: Components
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 2 4300 1000 10 15.1 14.9 3.45
74942302SPEC
8 files

EDA models: Components
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CAD files
ZIP

Electric models
ZIP

Download all 8 files as zip archive
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 2 4300 1000 10 15.1 15.4 3.45
Order Code Data­sheet
74941300SPEC
74941301SPEC
74941302SPEC
74942300SPEC
74942301SPEC
74942302SPEC
Samples
Order Code Data­sheet DownloadsPortsVT DC
(V (DC))		Working Voltage
(V (DC))		Cr
(mm)		L
(mm)		W
(mm)		H
(mm)		 Samples

Transformer for Battery Management Systems with integrated Common Mode Choke

The new WE-BMS series isolates the serial-connected components of the battery pack and the following BMS controllers from each other, suppressing any voltage differences and EMI that may occur. The design from Würth Elektronik provides a much larger physical creepage distance as opposed to other competitors, following market requirements for this kind of applications.

By maintaining the physical distance through the innovative design regardless of coated traces, high system safety and reliability can be achieved through special robustness against dryness or heat. Fully insulated wires are used for flat design and even better isolation properties.

Features and Benefits

Larger physical creepage distance than conventional design with the same footprint.
Larger physical creepage distance than conventional design with the same footprint.
Specific part numbers with AEC-Q200 qualification.
Specific part numbers with AEC-Q200 qualification.
Transformer and a common mode choke are included to filter common mode noise and electrical isolate the signals for BMS isolation and EMI noise suppression.
Transformer and a common mode choke are included to filter common mode noise and electrical isolate the signals for BMS isolation and EMI noise suppression.
WE-BMS series supports serial Daisy Chain, isoSPI, SPI and other signal isolation. Single and dual transformer for one or two channels are available.
WE-BMS series supports serial Daisy Chain, isoSPI, SPI and other signal isolation. Single and dual transformer for one or two channels are available.

BMS Layout Guidelines

The signal lines should be kept as short as possible and the transformer should be as close as possible to the isoSPI cable connector. A distance of <2 cm is suggested.
The signal lines should be kept as short as possible and the transformer should be as close as possible to the isoSPI cable connector. A distance of <2 cm is suggested.
IC should be placed between 1-2 cm from the transformer to avoid magnetic coupling.
IC should be placed between 1-2 cm from the transformer to avoid magnetic coupling.
For four-layer or multilayer PCBs, the area around the BMS traces, the BMS socket and the transformer should be exposed in all layers. The distance around this area to copper surfaces and traces should be at least 4 mm, depending on the system working voltage.
For four-layer or multilayer PCBs, the area around the BMS traces, the BMS socket and the transformer should be exposed in all layers. The distance around this area to copper surfaces and traces should be at least 4 mm, depending on the system working voltage.
What is a battery management system (BMS)?

What is a battery management system (BMS)?

A BMS is an electronic system that manages a rechargeable battery with the goal to make it safe and reliable.

Functions of a BMS:

  • Protecting the battery from operating outside its safe operation area
  • Monitoring its state of charge and state of health
  • Calculating secondary data and reporting that data
  • Controlling its environment
  • Authenticating it and/or balancing it
Why is a transformer needed in a BMS?

Why is a transformer needed in a BMS?

The individual cells in a battery pack are connected in series as well as the following BMS controllers. Between the components or PCBs connected in series, voltage differences and electromagnetic interference can occur. A transformer can be used to insolate the components from each other and suppress EMI interference. Therefore, WE-BMS transformer supports the BMS isolation and EMI noise suppression for a safe and reliable operation.

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