USB4 ESD devices provide optimum balance of protection and performance

Nexperia has two ESD protection devices optimised for use with retimers and redrivers on high-speed data lines. PESD2V8Y1BSF is intended to protect USB4 (Thunderbolt) interfaces, while PESD4V0Y1BCSF is aimed at USB4 and HDMI 2.1. These products use its TrEOS technology, which combines low clamping with low capacitance and high robustness.

The new devices offer vfTLP peak clamping voltages, which are even lower than USB4 protection solutions with no visible trigger voltage in the standard I(V) TLP curve. This aids in compensating for the decreased inductance between protection and retimer, thereby improving overall system-level ESD robustness. To comply with budget loss recommendations for ESD, these devices are created to have exceptionally low insertion loss (-0.29dB @ 10GHz) and return loss (-20.6dB @ 10GHz). Contrary to other solutions, the capacitance does not increase with operating voltage, providing the full RF performance up to the reverse standoff voltage.

The PESD2V8Y1BSF and PESD4V0Y1BCSF offer greater design flexibility than other ESD protection devices because they can be placed immediately next to the connector of the device which they are protecting. This means that the AC coupling capacitance is protected as well. On top, it places most of the line inductance between ESD protection and protected device to optimise system ESD performance.

“Nexperia enables design engineers to meet tight budgets on both insertion and return loss for high-speed USB4 data lines by providing devices that minimise the impact of ESD protection on overall system budget,” says Stefan Seider, senior product manager at Nexperia. “These devices offer the optimum balance between optimising system-level ESD robustness and RF performance.”

To maintain backward compatibility with older interface standards like USB3.2, which can be connected over USB Type-C, the PESD2V8Y1BSF has a reverse standoff voltage, VRWM = 2.8V, while the PESD4V0Y1BCSF has a VRWM = 4V making it suitable for HDMI 2.1 as well. The RF performance of the TrEOS technology used for both devices does not degrade over the operating voltage range. Apart from USB4 and HDMI 2.1, both parts can also be used to protect PCIe or DisplayPort interfaces.