onsemi NZQA6V8AXV5T3G

Overview

NZQA6V8AXV5T3G from onsemi is a quad unidirectional ESD protection diode in SOT-553 package, featuring 6.8 V breakdown voltage (V_BR = 6.47–7.14 V @ 1 mA), 4.3 V working peak reverse voltage (V_RWM), and clamping voltage ≤12 V at 13 A I_PP. It delivers IEC 61000-4-2 Level 4 (±8 kV contact) ESD protection for four independent signal lines in space-constrained interfaces such as USB 1.1/2.0 full-speed ports.

For engineers reviewing the NZQA6V8AXV5T3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 13 A transient current, low 1.0 µA leakage at V_RWM, 6.7 pF typical capacitance at 0 V bias, and compatibility with FR-4 PCB layouts requiring minimal trace clearance around the 1.6 mm × 1.2 mm SOT-553 footprint.

Technical Context

This device implements four independent unidirectional Zener-based ESD clamps sharing a common anode terminal (Pin 2), enabling bidirectional surge suppression across four signal paths using a single 5-pin surface-mount package. Its architecture targets low-capacitance, low-leakage protection without compromising clamping response time.

Each channel exhibits a specified breakdown voltage range of 6.47–7.14 V, a maximum clamping voltage of 12 V at 13 A peak pulse current, and thermal derating governed by R_JA = 327 °C/W. The device complies with MIL-STD-883C Method 3015-6 Class 3 and supports operation from −55 °C to +150 °C junction temperature.

Key Specifications

Pinout & Package

SOT-553 is a 5-lead plastic surface-mount package with gull-wing leads, measuring 1.60 mm × 1.20 mm × 0.60 mm (max height). Pin 1 is cathode for Channel 1; Pin 2 is common anode; Pins 3–5 are cathodes for Channels 2–4 respectively. Mounting requires standard reflow profile for Pb-free solder (peak 260 °C, 10 s).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ESD5Z6.8T5G and CM1213A-04SO, NZQA6V8AXV5T3G offers the lowest clamping voltage (≤12 V) and smallest capacitance (6.7 pF) in the smallest package (SOT-553), making it optimal for high-density USB and serial interfaces where signal integrity and board area are critical.

Availability

NZQA6V8AXV5T3G is available at Aetrix Electronics and suitable for USB full-speed interface protection, industrial serial port hardening, and medical sensor input safeguarding requiring stable component supply and long-term production continuity.

Supply support for NZQA6V8AXV5T3G 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 delivering energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, medical, and IoT applications.

NZQA6V8AXV5T3G belongs to the NZQA5V6AXV5 Series of integrated quad ESD protection diodes, designed specifically for compact, high-reliability transient suppression in USB, serial, and peripheral interfaces where board space and signal fidelity are constrained.

FAQ

What is the maximum clamping voltage of NZQA6V8AXV5T3G under IEC 61000-4-2 surge conditions?

The NZQA6V8AXV5T3G has a maximum clamping voltage of 12 V at 13 A peak pulse current (I_PP) under the 8/20 µs waveform defined in IEC 61000-4-2. This value is measured across each individual diode channel when subjected to the standardized ESD test pulse, ensuring downstream ICs see limited overvoltage during ±8 kV contact discharge events. The NZQA6V8AXV5T3G maintains this performance across its operating temperature range.

Does NZQA6V8AXV5T3G support USB 2.0 high-speed (480 Mbps) data lines?

No, NZQA6V8AXV5T3G is not recommended for USB 2.0 high-speed (480 Mbps) differential pairs due to its 6.7 pF typical capacitance at 0 V bias, which exceeds the ~1.5 pF limit needed to preserve signal integrity at 480 Mbps. The NZQA6V8AXV5T3G is qualified for USB 1.1 low-speed (1.5 Mbps) and full-speed (12 Mbps) applications, where its capacitance introduces negligible rise-time degradation.

How is the common anode configuration of NZQA6V8AXV5T3G implemented physically and electrically?

In the NZQA6V8AXV5T3G, Pin 2 serves as the common anode for all four unidirectional diodes. Each cathode (Pins 1, 3, 4, 5) connects to a separate signal line, while the shared anode must be tied to a low-impedance ground plane. This structure allows independent clamping of positive transients on each line to ground, without forward conduction between channels - a key advantage over bidirectional arrays in single-supply systems.

What is the thermal resistance (R_JA) of NZQA6V8AXV5T3G and how does it affect power derating?

The NZQA6V8AXV5T3G has a junction-to-ambient thermal resistance (R_JA) of 327 °C/W when mounted on a standard FR-4 board with minimum pad copper. This high R_JA necessitates strict derating: above 25 °C ambient, power dissipation must decrease by 3.05 mW/°C. For reliable operation at 85 °C ambient, the steady-state power per diode must remain below ~220 mW - consistent with its 380 mW rating at 25 °C.

Is NZQA6V8AXV5T3G compatible with lead-free reflow soldering processes?

Yes, NZQA6V8AXV5T3G is a Pb-free device rated for lead-free reflow soldering with a maximum peak temperature of 260 °C for 10 seconds, per J-STD-020. Its SOT-553 package is qualified for standard Pb-free reflow profiles, including ramp-soak-reflow cycles. The device's marking "G" suffix explicitly denotes Pb-free construction, and no special pre-conditioning or moisture sensitivity handling beyond MSL1 requirements is needed.