AUTOMOTIVE ELECTRONICS


Meet the challenge of accurate voltage sensing in electric vehicles with 


Designers of electric vehicles (EVs) and hybrid electric vehicles (HEVs) need to meet the demand for higher performance, faster charging,  voltage sensing for optimal 


H


owever, automotive applications are particularly challenging. Power electronics must function reliably for decades despite temperature extremes and the presence of high voltages that demand suitable isolation.


Voltage-sensing circuits for these applications must offer high bandwidth, low error and drift, and high common-mode transient immunity (CMTI) while meeting automotive standards like AEC-Q100. These requirements are especially relevant for critical components in EVs and HEVs, including inverters, DC/DC converters, and


onboard chargers.


 are well suited to these applications. These devices use advanced technology to achieve excellent performance over decades of exposure to harsh conditions. This article examines the operating  introduces a transformer-based example that uses iCoupler technology from Analog Devices, reviews its potential applications in EV/HEV development, and presents an evaluation board to help begin the design process.


Operating principles of transformer-based isolation 


  isolation between input and output circuits. This isolation can be achieved through several means, but transformer-based Figure 1) offer unique advantages for EV/HEV applications.


In transformer-based designs, isolation is achieved through transformer coupling. The basic principle of operation involves the following steps: • The input signal is converted into a high-frequency carrier signal.


• This carrier signal is then transmitted across the isolation barrier via a transformer.


• On the secondary side of the transformer, the original signal is reconstructed from the carrier.


 


20 JUNE 2025 | ELECTRONICS FOR ENGINEERS


The transformer serves two crucial functions. It provides galvanic isolation between input and output circuits, allowing safe measurement of high voltages and protecting sensitive circuitry. It also enables signal transfer without a direct electrical connection across the isolation barrier. Transformer-based isolation offers   reject common-mode voltages, crucial in noisy electrical environments. In addition,


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