Littelfuse Unveils Ultra-Low Capacitance TVS Diode Arrays

Littelfuse, an industrial technology manufacturing company shaping solutions for the safe and efficient transfer of electrical energy, announced AQ4315-01ETG and SP4315-01WTG, two new Bidirectional TVS Diode Arrays (SPA Diodes) that combine industry-leading low clamping voltage with ultra-low capacitance to protect today’s fastest automotive and consumer data interfaces from electrostatic discharge (ESD) without compromising signal integrity.

High-speed interfaces such as automotive ADAS, DisplayPort, and USB4 are increasingly vulnerable to ESD damage as data-line voltages drop below 1 V to save energy and reduce EMI. Conventional TVS diodes force a tradeoff between low clamping voltage and low capacitance, and many competing devices advertise a lower breakdown voltage while still clamping at levels that leave protected chips exposed to damage. The AQ4315-01ETG and SP4315-01WTG close that gap, holding clamping voltage to a typical 4.5 V to 6.5 V while suppressing ESD transients ranging from 8,000 V to 20,000 V down to well under 10 V at the protected device, an 800- to 2,000-times reduction in the voltage and current reaching the IC and keeping it safely within its Safe Operating Area (SOA).

“The industry is moving toward lower-voltage, higher-speed interfaces faster than traditional ESD protection can keep up,” said Sophia Hu, Assistant Product Marketing Manager, Diode Arrays, Littelfuse Protection Business Unit. “The AQ4315-01ETG and SP4315-01WTG give designers an extremely low clamping voltage without the capacitance penalty, so they gain stronger ESD and surge protection while preserving the signal integrity and board space their next-generation automotive and consumer designs demand.”

Key Features and Benefits

• Ultra-low clamping voltage: typical 4.5 V to 6.5 V during an ESD strike, as much as a tenfold improvement over comparable TVS diodes
• Ultra-low capacitance: 0.25 pF (AQ4315-01ETG) or 0.17 pF (SP4315-01WTG) to preserve high-speed signal integrity
• High ESD withstand: ±15 kV contact and ±20 kV air per IEC 61000-4-2; the AQ4315-01ETG also qualifies to ISO10605
• Automotive-grade reliability: AQ4315-01ETG is AEC-Q101 qualified and PPAP capable, rated -40°C to 150°C
• Industry-standard packaging: SOD-882/DFN1006 (AQ4315-01ETG) and 0201 WLCSP flip-chip (SP4315-01WTG) for fast, easy design-in
• Low leakage current: 50 nA maximum to minimize power consumption in battery-powered and always-on designs
• Broad protection margin: suppresses ESD transients of 8,000 V to 20,000 V to well under 10 V at the protected device.

Target Markets and Applications

• Automotive ADAS, DisplayPort, and Gigabit Multimedia Serial Link (GMSL) interfaces
• Gigabit Video Interface (GVIF) and Low Voltage Differential Signaling (LVDS) links
• 2.5G/5G/10G automotive and consumer Ethernet
• Thunderbolt 5.0, USB 3x, and USB4 consumer computing interfaces
• Consumer DisplayPort and other high-speed data line interfaces
• Industrial machine-to-machine communication protocols and legacy USB interfaces
• Space-constrained wearable and portable consumer electronics

The AQ4315-01ETG and SP4315-01WTG extend the Littelfuse SPA® Diode portfolio into a new class of ultra-low-voltage ESD protection as automotive and consumer interfaces adopt progressively lower data-line voltages, some running below 1 V. Both devices let design teams move quickly from inferior protection schemes to a solution engineered for today’s most sensitive, highest-speed interfaces.

Frequently Asked Questions

What makes the AQ4315-01ETG and SP4315-01WTG different from typical TVS diodes?

Most TVS diodes force a tradeoff between low clamping voltage and low capacitance. The AQ4315-01ETG and SP4315-01WTG combine clamping as low as 4.5 V with capacitance as low as 0.17 pF, providing strong ESD protection for high-speed interfaces without signal degradation.

What are the clamping voltage and capacitance specifications?

The AQ4315-01ETG has a typical clamping voltage of 6.5 V during a 7 A peak surge current and 0.25 pF of capacitance. The SP4315-01WTG clamps at 6.5 V with a 7 A peak current surge and has 0.17 pF of capacitance. Both withstand ESD strikes up to ±15 kV contact / ±20 kV air per IEC 61000-4-2.

What packages are the AQ4315-01ETG and SP4315-01WTG available in?

The AQ4315-01ETG ships in an automotive-grade SOD-882/DFN1006 package (1.0 x 0.6 mm); the SP4315-01WTG ships in a space-saving 0201 WLCSP flip-chip package (0.63 x 0.33 mm) for area-constrained consumer designs.

What applications are the AQ4315-01ETG and SP4315-01WTG designed for?

The AQ4315-01ETG targets automotive interfaces such as ADAS, DisplayPort, GMSL, GVIF, LVDS, and automotive Ethernet. The SP4315-01WTG targets consumer and computing interfaces, including Thunderbolt 5.0, USB 3x/USB4, DisplayPort, LVDS, and Ethernet.

When will the AQ4315-01ETG and SP4315-01WTG be available?

Littelfuse plans to make both devices available for sampling and production starting October 20, 2026, through Littelfuse and its global distributor network.