onsemi SZESD7551N2T5G

Overview

SZESD7551N2T5G from onsemi is a bi-directional ESD protection diode in X2DFN2 package, designed for ultra-low-capacitance (0.35 pF max) transient suppression on high-frequency signal lines. It features 3.3 V stand-off voltage, 10 V clamping at 1 A IPP, <1 ns response time, and AEC-Q101 qualification-ideal for USB 2.0 high-speed data lines and RF antenna interfaces.

For engineers reviewing the SZESD7551N2T5G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage under IEC 61000-4-2 Level 4, junction capacitance at 1 GHz, dynamic resistance (<2 Ω), leakage current (<50 nA @ 3.3 V), and wettable flank compatibility for AOI inspection.

Technical Context

The SZESD7551N2T5G implements a symmetric bi-directional TVS structure optimized for sub-1 GHz RF signal integrity. Its low dynamic resistance (0.55 Ω typ.) and ultra-low capacitance (0.22 pF @ 1 GHz) minimize insertion loss and signal distortion in antenna front-end and NFC applications.

It meets IEC 61000-4-2 Level 4 (±25 kV contact/air) and ISO 10605 (±30 kV, 150 pF/2 kΩ), with clamping voltage measured per TLP pulse (1 A/3 A) and validated using oscilloscope waveform capture-not just peak voltage thresholds.

Key Specifications

Pinout & Package

Package: X2DFN2 (1.00 mm × 0.60 mm × 0.37 mm, 0.65 mm pitch), Pb-free, halogen-free, RoHS-compliant surface-mount package with exposed cathode pad for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ESD7551N2T5G and CM1213A-03SR, the SZESD7551N2T5G delivers automotive-grade reliability and lowest RF insertion loss-critical for antenna and high-speed serial interface protection where signal fidelity and qualification compliance are jointly mandatory.

Availability

SZESD7551N2T5G is available at Aetrix Electronics and suitable for USB 2.0 high-speed interfaces, mobile antenna front-ends, and automotive infotainment display ports requiring stable component supply and full AEC-Q101 traceability.

Supply support for SZESD7551N2T5G 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 (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The SZESD7551N2T5G belongs to onsemi's ESD7551 family-engineered specifically for ultra-low-capacitance, high-frequency ESD protection in space-constrained RF and high-speed digital systems.

FAQ

What is the maximum clamping voltage of SZESD7551N2T5G under IEC 61000-4-2 testing?

The SZESD7551N2T5G does not specify a single "maximum clamping voltage" under IEC 61000-4-2, as the standard defines pass/fail by peak current-not clamping. Instead, onsemi characterizes it via TLP: 10 V clamping at 1 A IPP and 13 V at 3 A IPP. These values represent the actual voltage seen by protected circuitry during standardized ESD transients, and the SZESD7551N2T5G consistently achieves them across production lots.

Is SZESD7551N2T5G compatible with lead-free reflow profiles?

Yes, SZESD7551N2T5G supports JEDEC J-STD-020D-compliant lead-free reflow, with a maximum lead solder temperature of 260°C for 10 seconds. Its X2DFN2 package is qualified for standard Pb-free assembly processes, and the device's thermal resistance (R_JA = 400°C/W) ensures safe operation during typical reflow ramp rates and soak times used in high-volume SMT lines.

Does SZESD7551N2T5G require external biasing or control signals?

No, SZESD7551N2T5G is a passive, bi-directional TVS diode requiring no external bias, power, or control. It operates solely on voltage threshold behavior: conducting only when reverse voltage exceeds ~5 V (breakdown) or forward voltage exceeds ~0.7 V. This makes the SZESD7551N2T5G ideal for always-on protection on unpowered or intermittently active signal lines like antenna feeds or USB connectors.

How does the capacitance of SZESD7551N2T5G vary with frequency?

SZESD7551N2T5G exhibits 0.25 pF at 1 MHz, 0.22 pF at 1 GHz, and remains ≤0.35 pF up to 6 GHz per datasheet CV curves. This flat, ultra-low profile-unlike conventional diodes whose capacitance rises at lower frequencies-is achieved through optimized junction geometry and low-parasitic packaging, ensuring minimal impact on 5G NR and Wi-Fi 6E antenna matching networks.

Can SZESD7551N2T5G be used in place of a unidirectional ESD diode?

SZESD7551N2T5G is inherently bi-directional and should not replace unidirectional diodes in circuits requiring DC blocking or polarity-specific clamping (e.g., power rail protection). However, for AC-coupled signal lines like USB D+/D−, RF antennas, or MIPI clock pairs, its symmetric clamping provides superior protection without polarity constraints-and the SZESD7551N2T5G's 3.3 V stand-off ensures compatibility with common 3.3 V I/O domains.