New Semtech IC Closes USB-PD VBus Protection Gap at 53V – All About Circuits

New Semtech IC Closes the USB-PD VBus Protection Gap at 53 V Semtech has introduced a new circuit protection device designed to address a critical vulnerability in USB Power Delivery Extended Power Range (EPR) systems. The TDS5311P, part of the SurgeSwitch® family, is engineered to protect power buses (VBus) operating at up to 53 V, specifically targeting the growing demand for reliable 48 V USB PD EPR applications in industrial equipment, rugged mobility devices, and high-performance portable systems. As USB PD EPR adoption expands into environments requiring industrial-grade reliability, designers face a persistent protection gap: conventional transient voltage suppression (TVS) diodes exhibit inconsistent clamping voltage that shifts with current levels and temperature fluctuations. This variability can compromise the safety and longevity of sensitive downstream components. The TDS5311P overcomes this limitation through its surge-rated FET architecture. Unlike standard TVS diodes, the device maintains a nearly constant clamping voltage from the first microsecond of a surge event through maximum rated current, across the full industrial temperature range of -40°C to +125°C. This behavior ensures predictable and stable protection under varying operating conditions. Key specifications of the TDS5311P include a high-energy transient current rating of up to 24A (tp = 8/20μs) and compliance with the ±1kV surge standard per IEC 61000-4-5 (RS = 42Ω, CS = 0.5μF). The device also features high electrostatic discharge (ESD) withstand voltage, rated at +/-20kV (contact) and +/-25kV (air) per IEC 61000-4-2, and high electrical fast transient (EFT) withstand voltage of ±4kV per IEC 61000-4-4. Packaged in a compact 2.0 x 2.0 mm, 6-pin DFN format, the TDS5311P offers significant board space savings compared to traditional SMAJ and SMBJ packaged devices. This minor footprint makes it well-suited for space-constrained designs where performance and reliability are paramount. Semtech positions the TDS5311P as the industry’s first circuit protection device to deliver near-constant clamping voltage for USB PD EPR applications at 48 V. By closing the protection gap at 53 V, the component enables designers to meet the stringent reliability demands of next-generation USB power systems without sacrificing efficiency or size.