onsemi NSPU3051N2T5G

Overview

NSPU3051N2T5G from onsemi is a unidirectional ESD and surge protection diode designed for I/O line protection in portable electronics. It delivers 5.5 V working reverse voltage, ±30 kV IEC 61000−4−2 contact ESD immunity, 36 A peak pulse current (8/20 µs), 7.5–9.5 V clamping voltage at 36 A, and 100–130 pF junction capacitance - enabling robust, low-capacitance protection for USB VBUS/CC, microphone, and GPIO lines.

For engineers reviewing the NSPU3051N2T5G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage under 36 A surge, sub-130 pF capacitance for high-speed signal integrity, unidirectional polarity alignment with supply-rail referenced I/O, and X2DFN2 package compatibility with space-constrained PCB layouts.

Technical Context

The NSPU3051N2T5G is a single-channel, unidirectional TVS diode configured as a cathode-to-GND clamp. Its breakdown voltage (5.7–9.1 V) ensures reliable turn-on above 5.5 V working voltage while maintaining low leakage (<0.1 µA at VRWM). The device uses silicon avalanche structure optimized for fast response to sub-nanosecond ESD transients.

It meets IEC 61000−4−2 Level 4 (±30 kV contact) and IEC 61000−4−5 (36 A, 8/20 µs lightning surge), with dynamic resistance of 0.025 Ω measured via TLP at 100 ns. Clamping performance is characterized across 8 A, 16 A, and 36 A pulses, confirming stable voltage suppression up to rated surge current.

Key Specifications

Pinout & Package

NSPU3051N2T5G is housed in the X2DFN2 (Case 714AB) surface-mount package: 1.00 mm × 0.60 mm × 0.37 mm, 0.65 mm pitch, two-terminal configuration with exposed cathode pad for thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar unidirectional ESD protection applications.

Compared with SMAJ5.0A and ESD5Z5.0T1G, the NSPU3051N2T5G uniquely combines Level 4 ESD rating, 36 A surge capability, and ≤130 pF capacitance in a 1.0×0.6 mm footprint - making it optimal for miniaturized, high-compliance USB and audio interfaces where signal fidelity and board space are constrained.

Availability

NSPU3051N2T5G is available at Aetrix Electronics and suitable for USB Type-C interface protection, portable audio subsystems, and compact IoT sensor node designs requiring stable component supply and full IEC 61000−4−2/−5 compliance.

Supply support for NSPU3051N2T5G includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, delivering power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The NSPU3051N2T5G belongs to onsemi's ESD protection diode product line, engineered specifically for ultra-compact, high-fidelity I/O protection in battery-powered portable devices where ESD immunity, low capacitance, and minimal leakage are critical.

FAQ

What is the polarity configuration of the NSPU3051N2T5G?

The NSPU3051N2T5G is a unidirectional TVS diode with anode (Pin 2) connected to the protected line and cathode (Pin 1) tied to ground. This configuration allows it to clamp positive transients only - ideal for protecting supply-referenced I/O such as USB VBUS or microphone bias lines. Its polarity is fixed and not reversible; using it in reverse would prevent proper clamping. The NSPU3051N2T5G datasheet specifies this arrangement explicitly in the marking diagram and pinout table.

Does the NSPU3051N2T5G meet IEC 61000−4−2 Level 4 for both contact and air discharge?

Yes, the NSPU3051N2T5G is rated for ±30 kV contact discharge per IEC 61000−4−2 Level 4, and also achieves ±30 kV air discharge. This dual rating is confirmed in Table 1 of the official onsemi datasheet (Rev. 5, May 2024). The device's low clamping voltage and fast response enable consistent pass performance across both test methods, making it suitable for final-product certification in smartphones, tablets, and other handheld consumer electronics where user interaction is frequent.

What is the maximum junction temperature range for the NSPU3051N2T5G?

The NSPU3051N2T5G has an operating junction temperature range of −65 °C to +150 °C, as specified in Table 1 of its datasheet. This wide range supports deployment in harsh environments such as automotive cabin modules or industrial edge sensors. Thermal performance is enhanced by the X2DFN2 package's exposed cathode pad, which improves heat conduction to the PCB ground plane. Derating is not required within this range, and the NSPU3051N2T5G maintains full ESD/surge specifications across the entire span.

Can the NSPU3051N2T5G be used for bidirectional signal lines like USB D+/D−?

No - the NSPU3051N2T5G is unidirectional and unsuitable for bidirectional data lines such as USB 2.0 D+ and D−. Its single-anode-to-cathode structure only protects against positive transients relative to ground. For bidirectional protection, a symmetric dual-diode array (e.g., NSPU3052) or dedicated bidirectional TVS is required. Using the NSPU3051N2T5G on D+/D− would leave negative ESD events unprotected and risk interface failure. Always verify polarity alignment before placing the NSPU3051N2T5G in circuit.

How does the junction capacitance of the NSPU3051N2T5G affect high-speed signal integrity?

The NSPU3051N2T5G exhibits 100–130 pF junction capacitance at 0 V and 1 MHz, measured per Table 3. This low value minimizes signal attenuation and timing skew on moderate-speed lines such as USB 2.0 (480 Mbps), analog audio, and I²C. It avoids the bandwidth-limiting effects seen with higher-capacitance alternatives (>300 pF), preserving rise/fall times and preventing bit errors or audio distortion. For reference, the NSPU3051N2T5G's capacitance is verified in Figure 10 of the datasheet and remains stable across bias conditions relevant to protected I/O rails.