First ESD protection diodes for 48V EV communications networks

Nexperia has introduced the industry’s first ESD diodes designed to protect 48V automotive data communications networks against the destructive effects of ESD events. This new portfolio of six robust AEC-Q101 qualified devices covers the required higher reverse working maximum voltage (VRWM) for increasingly common 48V board nets. This ultimately saves PCB space and system cost while maintaining signal integrity even at higher data rates.

While data communications protocols like CAN and its flexible data rate variant, CAN-FD, as well as LIN and FlexRay, have been around for several decades, their proven reliability in lower-speed applications means they continue to feature in even the most recent automobiles, including EV and HEV models. However, unlike conventional ICE-powered vehicles, which typically feature a 12V battery, or commercial vehicles with a 24V battery, the higher efficiency requirements of EVs and HEVs are driving them increasingly towards using a 48V battery to power various electrical systems, including legacy communications networks.

“Until now, automotive equipment manufacturers lacked suitable ESD protection solutions specifically designed for 48V data lines,” explains Alexander Benedix, head of Product Group Protection and Filtering at Nexperia. “As a result, they often had to rely on workarounds – either including an additional 12V power rail or connecting several lower-voltage (36V) protection diodes in parallel – to ensure their systems were adequately protected. With this new portfolio, designers working with 48V board nets can now save space and cost while delivering best-in-class ESD protection for their automotive networks.”

For design flexibility, this portfolio features ESD diodes with 54V (PESD2CANFD54VT-Q and PESD2CANFD54LT-Q), 60V (PESD2CANFD60VT-Q and PESD2CANFD60LT-Q) and 72V (PESD2CANFD72VT-Q and PESD2CANFD72LT-Q) maximum reverse working voltages (VRWM). These ultra-low capacitance (down to 3.4pF) devices are packaged in a standard SOT23 package. The optimised capacitance ensures that signal integrity is not impacted even in higher-speed protocols like CAN-FD.