Littelfuse Adds Ultra-Low-Capacitance TVS Diodes for High-Speed Interfaces

Littelfuse has introduced the AQ4315-01ETG and SP4315-01WTG bidirectional TVS diode arrays, with capacitance as low as 0.17 pF for protecting high-speed automotive and consumer data interfaces.

As data-line voltages fall below 1 V, protection devices have less room to clamp an ESD event before the transient reaches sensitive circuitry. At the same time, adding too much capacitance to interfaces such as USB4, DisplayPort or automotive Ethernet can affect signal integrity.

The two new Littelfuse devices are intended to address both sides of that problem, with low clamping voltage alongside the low capacitance needed for high-speed links.

Clamping ESD Without Loading the Data Line

The AQ4315-01ETG has a capacitance of 0.25 pF, while the SP4315-01WTG is specified at 0.17 pF.

Both devices have a typical clamping voltage of 6.5 V at a 7 A peak surge current and withstand ±15 kV contact and ±20 kV air discharge under IEC 61000-4-2.

Littelfuse says the devices can suppress ESD transients ranging from 8 kV to 20 kV to below 10 V at the protected device. The company also claims lower clamping voltage than comparable TVS diodes, while retaining the very low capacitance required on high-speed signal lines.

Leakage current is limited to 50 nA maximum, which also makes the parts suitable for battery-powered and always-on systems.

Separate Devices for Automotive and Consumer Interfaces

The AQ4315-01ETG is aimed primarily at automotive applications. It is AEC-Q101 qualified and PPAP capable, supports ISO 10605 requirements and is rated for operation from -40°C to +150°C.

Applications include ADAS camera systems, GMSL, GVIF, LVDS, DisplayPort and 2.5G, 5G and 10G automotive Ethernet. The device is supplied in a 1.0 × 0.6 mm SOD-882/DFN1006 package.

The SP4315-01WTG targets consumer and computing interfaces including Thunderbolt 5, USB 3.x, USB4, DisplayPort, LVDS and Ethernet. It is supplied in a smaller 0.63 × 0.33 mm 0201 WLCSP flip-chip package for designs where board space is limited.

Littelfuse plans to make both devices available for sampling and production from October 20, 2026.

Learn more and read the original announcement at Littelfuse.com.

Technology Overview

The Littelfuse AQ4315-01ETG and SP4315-01WTG are bidirectional TVS diode arrays for ESD protection on high-speed data interfaces. Capacitance is specified at 0.25 pF for the automotive-focused AQ4315-01ETG and 0.17 pF for the SP4315-01WTG. Both support ±15 kV contact and ±20 kV air discharge under IEC 61000-4-2.

FAQs

What capacitance do the new Littelfuse TVS diode arrays have?

The AQ4315-01ETG is specified at 0.25 pF, while the SP4315-01WTG has a capacitance of 0.17 pF.

Which high-speed interfaces can they protect?

Target interfaces include automotive Ethernet, GMSL, GVIF, LVDS and DisplayPort, as well as USB 3.x, USB4, Thunderbolt 5 and consumer Ethernet.

Which Littelfuse device is qualified for automotive use?

The AQ4315-01ETG is AEC-Q101 qualified and PPAP capable, supports ISO 10605 requirements and operates from -40°C to +150°C.