Nexperia's USB4 ESD diode device achieves an excellent balance between protection and performance

     Nexperia announced the launch of two optimized electrostatic discharge (ESD) protective diode devices for retimers and signal repeaters in high-speed data lines. PESD2V8Y1BSF is specially designed to protect USB4 (Thunderbolt) interface, while PESD4V0Y1BCSF is applicable to USB4 and HDMI 2.1. Both products use Nexperia's mature TrEOS technology, which combines the advantages of low clamping, low capacitance and high robustness.

     Retimer and signal repeater are commonly used devices to design high-speed USB4 interface. They require short circuit board routing to reduce parasitic inductance, but also unexpectedly reduce overall system level ESD robustness. PESD2V8Y1BSF and PESD4V0Y1BCSF have lower peak clamping voltage of ultra fast transmission line pulse (vfTLP), even lower than USB4 protection solution without obvious trigger voltage in standard I (V) TLP curve. This helps compensate for the reduced inductance between the protection device and the retimer, thereby improving overall system level ESD robustness. In order to reach the recommended value of ESD budget loss, both devices can provide ultra-low insertion loss (-0.29 dB at 10 GHz) and return loss (- 20.6 dB at 10 GHz). Unlike other solutions, capacitors do not increase with the operating voltage, providing complete RF performance up to the reverse cut-off voltage.

     Compared with other ESD protective diode devices, PESD2V8Y1BSF and PESD4V0Y1BCSF can be directly placed next to the connector of the protected device, thus providing greater design flexibility. This means that the AC coupling capacitor will also be protected. In addition, it places most line inductors between ESD protection and protected devices to optimize the ESD performance of the system. Stefan Seider, senior product manager of Nexperia, said: "Nexperia helps design engineers meet the insertion loss and return loss requirements of high-speed USB4 data lines with limited budget by providing devices that minimize the impact of ESD protection on the total budget. These two devices achieve an excellent balance between optimizing system level ESD robustness and RF performance."

     In order to be backward compatible with the old interface standards (such as USB3.2) that can be connected through USB Type-C, PESD2V8Y1BSF has a 2.8V reverse cut-off voltage VRWM, while PESD4V0Y1BCSF has a 4V VRWM, so it is also applicable to HDMI 2.1. Both devices use TrEOS technology, and their RF performance will not decline within the operating voltage range. In addition to USB4 and HDMI 2.1, the two devices can also be used to protect PCIe and DisplayPort interfaces.